Tính nhanh:
1,1 + 2,2 + 3,3 + ... + 8,8 + 9,9 =
\(\frac{1}{2}\) : 0,5 - \(\frac{1}{4}\):0,25 + \(\frac{1}{8}\): 0,125 + \(\frac{1}{10}\) 0,1=
23,45 : 12,5 : 0,8 =
tính bằng cách hợp lí nhất:
a) 1,1+2,2+3,3+...+8,8+9,9
b) 1/2:0,5-1/4:0,25+1/8:0,125-1/10:0,1
KBCA11D21
Nhận thấy :
D1ˆ=D2ˆD1^=D2^
Ta có : D1ˆ=90o=B1ˆD1^=90o=B1^
D2ˆ=90o−C1ˆD2^=90o−C1^
→B1ˆ=C1ˆ→B1^=C1^
Xét ΔABKΔABK và ΔACDΔACD
BAKˆ=CADˆ=90oBAK^=CAD^=90o
AB=AC(gt)AB=AC(gt)
B1ˆ=C1ˆB1^=C1^
→ΔABK=ΔACD(g.c.g)→ΔABK=ΔACD(g.c.g)
→AK=AD(đpcm
A)1,1+2,2+3,3+...................+8,8+9,9
=(1,1+9,9)+(2,2+8,8)+..........................+(4,4+6,6)+5,5
= 11+11+11+11+5,5=55+5,5=60,5
b) 1/2:0,5-1/4:0,25+1/8:0,125-1/10:0,1
=1/2 nhân 2-1/4 nhân 4+1/8 nhân 8-1/10 nhân 10
=1-1+1-1=0+0=0
\(\frac{1}{2}\) : 0,5 - \(\frac{1}{4}\):0,25 + \(\frac{1}{8}\): 0,125 - \(\frac{1}{10}\):0,1
tính nhanh nha
\(\frac{1}{2}:0,5-\frac{1}{4}:0,25+\frac{1}{8};0,125-\frac{1}{10}:0,1=\frac{1}{2}:\frac{1}{2}-\frac{1}{4}:\frac{1}{4}+\frac{1}{8}:\frac{1}{8}-\frac{1}{10}:\frac{1}{10}=1-1+1-1=0+0=0\)
Tính nhanh:
a) 2010 x 97 + 2010 : 0,5 + 2010
b) 1,1 + 2,2 + 3,3 + 4,4 + 4,5 + 6,6 + 7,7 + 8,8 + 9,9 + 6 và 1/2
a) = 194970 + 4020 + 2010 = 201000
b)
= ( 1,1 + 9,9) + ( 2,2 + 8,8) + ( 3,3+7,7) + ( 4,4 + 6,6) + 4,5 + 6 + 1/2
= 10 + 10 + 10 + 10 + 4,5 + 6 + 1/2
= 51
Tính bằng cách thuận tiên nhất :
\(\frac{1}{2}\): 0,5 - \(\frac{1}{4}\): 0,25 + \(\frac{1}{8}\): 0,125 - \(\frac{1}{10}\): 0,1 =
em ơi cái này = 0 . Anh chắc chắn vs em 100000000000000000000000000000000000000000000000000000000000000000%
Anh lớp 7 mà
\(\frac{1}{2}:0,5-\frac{1}{4}:0,25+\frac{1}{8}:0,125-\frac{1}{10}:0,1\)
\(=\left(0,5:0,5\right)-\left(0,25:0,25\right)+\left(0,125:0,125\right)-\left(0,1:0,1\right)\)
\(=1-1+1-1\)
\(=\left(1\times2\right)-\left(1\times2\right)\)
\(=2-2\)
\(=0\)
bằng 0 đấy chắc chắn 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000% luôn
Tính nhanh
a) 2 a 4,8 x 0,5 + 4 x 16 x 0,25 + 20 : 10 x 0,5
b) 12,5 x 3,14 x 8 + 16 x 0,125 x 1,57
c) \(\frac{22222}{55555}+\frac{3}{10}\)
\(A=\frac{0,375-0,3+\frac{3}{11}+\frac{3}{12}}{-0,625+0,5-\frac{5}{11}-\frac{5}{12}}+\frac{1,5+1-0,75}{2,5+\frac{5}{3}-1,25}\)
\(A=\frac{3\left(0,125-0,1+\frac{1}{11}+\frac{1}{12}\right)}{-5\left(0,125-0,1+\frac{1}{11}+\frac{1}{12}\right)}+\frac{3\left(0,5+\frac{1}{3}-0,25\right)}{5\left(0,5+\frac{1}{3}-0,25\right)}=-\frac{3}{5}+\frac{3}{5}=0\)
sao bạn tự đăng tự giải thế? hay là bạn giải cho ai à?
\(\frac{1}{2}\): 0,5 - \(\frac{1}{4}\): 0,25 + 12,5% : 0,125 - \(\frac{1}{10}\): 0,1
T_T Đây là bài cuối cùng trong đề thi toán của mình và cũng là bài mình buồn nhất đang làm gần hết bài thì cô bắt nộp bài hu hu. T_T
=1/2x2-1/4x4+12,5%x8-1/10x10
=1-1+1-1
=0
\(\frac{1}{2}:0,5-\frac{1}{4}:0,25+12,5\%:0,125-\frac{1}{10}:0,1=\frac{1}{2}:\frac{1}{2}-\frac{1}{4}:\frac{1}{4}+\frac{1}{8}:\frac{1}{8}-\frac{1}{10}:\frac{1}{10}=\frac{1}{2}.2-\frac{1}{4}.4+\frac{1}{8}.8-\frac{1}{10}.10=1-1+1-1=0\)
Tính 243,5-12,5 nhân 3,3+12,345 Tính nhanh 23,45+46,23+27,55+53,77 12,5 nhân 4 nhân 0,25 nhân 0,8
Tính nhanh:
1/2 : 0,5 - 1/4 : 0,25 +1/8 : 0,125 - 1/10 : 0,1