TÍNH NHANH
a)15x14-1
13x15+14
b)9x(262626+88888)
272727 99999
c)1+2+3+4+5+6+7+8+9
10
d)4343+4343+4343+4343
7171 7171 7171 7171
bài phân số
1.Tìm y
a) y3 + 3y = 12 x 11
b) 64 x y + 225 = 700 - 75 - 36 x y
2.Tính
a)\(\frac{4343}{7171}+\frac{4343}{7171}+\frac{4343}{7171}+\frac{4343}{7171}\)
b) A = \(\frac{1}{33}\times\left(\frac{33}{12}+\frac{3333}{2020}+\frac{333333}{303030}+\frac{33333333}{42424242}\right)\)
bài 2
a] = 3 x \(\frac{4343}{7171}\)= \(\frac{17372}{7171}\)= \(\frac{172}{71}\)
b] = \(\frac{1}{33}\)x \(\frac{44}{7}\)= \(\frac{1}{3}\)x \(\frac{4}{7}\)=\(\frac{4}{21}\)
bài 1
a] y là 9
b] <=> 64y + 36y = 700 - 75 - 225
<=> 100y = 400
<=> y = 4
trên lớp cô sửa rồi nên mình giải luôn:
1) Tìm y
a) y3 + 3y = 12 x 11
y3 + 3y = 132
y x 10 + 3 + 3 x 10 + y = 132
( y x 10 + y ) + ( 3 x 10 + 3 ) = 132
11 x y + 33 = 132
11 x y = 132 - 33
11 x y = 99
y = 99 : 11
y = 9
b) 64 x y + 225 = 700 - 75 - 36 x y
64 x y + 225 = 625 - 36 x y
64 x y + 36 x y = 625 -225
64 x y + 36 x y = 400
( 64 + 36 ) x y = 400
100 x y = 400
y = 400 : 100
y = 4
2) Tính
a) \(\frac{4343}{7171}+\frac{4343}{7171}+\frac{4343}{7171}+\frac{4343}{7171}\)
\(=\frac{4343}{7171}\times4\)
\(=\frac{43}{71}\times4\)
\(=\frac{172}{71}\)
b) A = \(\frac{1}{33}\times\left(\frac{33}{12}+\frac{3333}{2020}+\frac{333333}{303030}+\frac{33333333}{42424242}\right)\)
Ta có:
\(\frac{3333}{2020}=\frac{3333:101}{2020:101}=\frac{33}{20}\)
\(\frac{333333}{303030}=\frac{333333:10101}{303030:10101}=\frac{33}{30}\)
\(\frac{33333333}{42424242}=\frac{33333333:1010101}{42424242:1010101}=\frac{33}{42}\)
A = \(\frac{1}{33}\times\left(\frac{33}{12}+\frac{33}{20}+\frac{33}{30}+\frac{33}{42}\right)\)
A = \(\frac{1}{33}\times33\left(\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\right)\)
A = 1 x \(\left(\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\right)\)
A = 1 x \(\left(\frac{1}{3x4}+\frac{1}{4x5}+\frac{1}{5x6}+\frac{1}{6x7}\right)\)
A = 1 x \(\left(\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}\right)\)
A = 1 x \(\left(\frac{1}{3}-\frac{1}{7}\right)\)
A = 1 x \(\left(\frac{7}{21}-\frac{3}{21}\right)\)
A = 1 x \(\frac{4}{21}\)
A = \(\frac{4}{21}\)
1,kiểm tra các số có = nhau ko
a, -4/5 và 2/10 b,3/2 và 9/6 c,1/-2 và -40/80
d,-12/5 và -144/25 e,2525/4343 và 25/43 f,-26/17 và 262626/171717
\(a,-\dfrac{4}{5}=-0,8\) \(;\dfrac{2}{10}=0,2\) \(\Rightarrow\) Ko bằng nhau
\(b,\dfrac{3}{2}=1,5;\dfrac{9}{6}=\dfrac{3}{2}=1,5\Rightarrow\) Bằng nhau
\(c,\dfrac{1}{-2}=-0,5;-\dfrac{40}{80}=-\dfrac{1}{2}=-0,5\Rightarrow\) Bằng nhau
\(d,-\dfrac{12}{5}=-2,4;-\dfrac{144}{25}=-5,76\Rightarrow\) Ko bằng nhau
\(e,\dfrac{2525}{4343}=\dfrac{25}{43};\dfrac{25}{43}=\dfrac{25}{43}\)\(\Rightarrow\) Bằng nhau
\(f,-\dfrac{26}{17}\approx-1,53;\dfrac{262626}{171717}=\dfrac{26}{17}\approx1,53\) \(\Rightarrow\) Ko bằng nhau
Tính nhanh:
\(\frac{15x14-1}{15x13+14}\) Và \(9x\left(\frac{262626}{272727}+\frac{88888}{99999}\right)\)
Ta có: 15x14-1/15x13+14=15x13+15-1/15x13+14=15x13+14/15x13+14=1
\(\frac{15x14-1}{15x13+14}\)
\(\frac{15x13}{15x13+14}\)=\(\frac{1}{14}\)
\(a,\frac{1}{10}+\frac{2}{10}+\frac{3}{10}+\frac{4}{10}+\frac{5}{10}+\frac{6}{10}+\frac{7}{10}+\frac{8}{10}+\frac{9}{10}\)
\(b,9x\left(\frac{262626}{272727}+\frac{88888}{99999}\right)\)
a,
\(=\frac{1+2+3+4+5+6+7+8+9}{10}=\frac{45}{10}=\frac{9}{2}\)
b,\(=9\times\left(\frac{26\times10101}{27\times10101}+\frac{8\times11111}{9\times11111}\right)=9\times\left(\frac{26}{27}+\frac{8}{9}\right)=9\times\frac{50}{27}=\frac{50}{3}\)
k cho mk nha!!!!!!!!!!!!!
Mk cần gấp các bạn ơi !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!?
là dạng tính nhanh nhé !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!?
3434/7171+X=1234/2468 toan lop 4
\(\frac{3434}{7171}+x=\frac{1234}{2468}\)
\(\frac{34}{71}+x=\frac{1}{2}\)
\(x=\frac{1}{2}-\frac{34}{71}\)
\(x=\frac{3}{142}\)
Tính nhanh
a) 27 x 45 + 55 x 27/ 2 + 4 + 6 + 8 + ... + 16 + 18
b) 3737 x 43 - 4343 x 37/ 2 + 4 + 6 + 8 + ... + 98 + 100
a) \(\frac{27.45+55.27}{2+4+6+8+...+16+18}=\frac{27.\left(45+55\right)}{\left(2+18\right)+\left(16+4\right)+\left(14+6\right)+\left(12+8\right)}\)
\(=\frac{27.100}{20+20+20+20}=\frac{2700}{20.4}=\frac{2700}{80}=\frac{135}{4}\)
b) Lười
Làm giống câu a nhé
bài 1 Tính
a) C =\(\frac{101+100+99+98+....+3+2+1}{101-100+99-98+....+3-2+1}\)
b) D = \(\frac{3737\cdot43-4343\cdot37}{2+4+6+....+100}\)
C = \(\frac{101+100+99+98+...+3+2+1}{101-100+99-98+...+3-2+1}\)
\(C=\frac{\left(101+1\right).101:2}{1+1+...+1+1}\)
\(C=\frac{5151}{51}\)
\(C=101\)
b) \(D=\frac{3737.43-4343.37}{2+4+6+...+100}\)
\(D=\frac{37.101.43-43.101.37}{2+4+6+...+100}\)
\(D=\frac{0}{2+4+6+...+100}\)
\(D=0\)
a) \(C=\frac{101+100+99+98+...+3+2+1}{101-100+99-98...+3-2+1}\)
\(=\frac{\left(101+1\right).\left[\left(101-1\right):1+1\right]:2}{\left(101-100\right)+\left(99-98\right)+\left(3-2\right)+1}\)
\(=\frac{102.101:2}{1+1+...+1}\)
\(=\frac{51.101}{51}\)
\(=101.\)
3737*43-4343*37/2+4+6+...+100
Phân số nha
Trả lời
3737.43-4343.37/2+4+6+...+100
=37.101.43-43.101.37/2+4+6+...+100
=0/100
=0
Chúc bạn học tốt !
Cái này có dấu hiệu nè , bạn nên nhớ số có dạng \(\overline{abab}\)đề chia hết cho \(\overline{ab}\)và 101 nha
3737.43-4343.37/2+4+6+...+100
=37.101.34-43.101.37/2+4+6+...+100
=0/2+4+6+...+100
=0
Hok tốt !
\(\frac{3737\cdot43-4343\cdot37}{2+4+6+...+100}\)
\(=\frac{37\cdot101\cdot43-43\cdot101\cdot37}{2+4+6+...+100}\)
\(=\frac{0}{2+4+6+...+100}\)
\(=0\)
=))
tính hợp lí :
3737 x 43 - 4343 x 7 / 2 + 4 + 6 + ... + 100
\(\frac{3737.43-4343.7}{2+4+6+...+100}\)
\(=\frac{37.101.43-4343.37}{2+4+6+...+100}\)
\(=\frac{37.4343-4343.37}{2+4+6+...+100}\)
\(=\frac{0}{2+4+6+...+100}\)
Ta có : Tử số bằng 0 \(\Rightarrow\) phân số trên bằng 0
\(=0\)
\(\frac{3737.43-4343.7}{2+4+6+....+100}\)
=\(\frac{37.101.43-4343.37}{2+4+6+...+100}\)
\(=\frac{37.4343-4343.37}{2+4+6+....+100}\\ =\frac{0}{2+4+6+...+100}\\ =0\)