Tinh nhanh
35×7-70-5+25
Thuc hien phep tinh
A, 3/7 + 1/2 - (-3)/70
B, 3/5 + -1/25 - 35/100
C, 5/12 - 3/-16 + 3/4
D, 5/15 + 4/-12 + 1/7 - 1/-6
a,3/7 +1/2-[-3]/70
=13/14 -[-3]/70
=65/70 -[-3]/70
=34/35
b,3/5+-1/25 -35/100
=14/25 - 35/100
=56 /100 -35/100
= 21/100
c ,5/12 -3/-16+3/4
=29/48 +3/4
= 29/48 +36/48
=65/48
d, 5/15 +4/-12 +1/7 -1/-6
= 1/3 +1/-3 +1/7-1/-6
=0+1/7-1/-6
= 13/42
A.\(\dfrac{3}{7}+\dfrac{1}{2}+\dfrac{\left(-3\right)}{70}\)
=\([\dfrac{30}{70}+\dfrac{\left(-3\right)}{70}]\)+\(\dfrac{1}{2}\)
= \(\dfrac{27}{70}+\dfrac{35}{70}\)
=\(\dfrac{62}{70}=\dfrac{31}{35}\)
B.\(\dfrac{3}{5}+\dfrac{-1}{25}-\dfrac{35}{100}\)
=\(\dfrac{60}{100}+\dfrac{-4}{100}-\dfrac{35}{100}\)
=\(\dfrac{60+\left(-4\right)-35}{100}\)
=\(\dfrac{21}{100}\)
C.\(\dfrac{5}{12}-\dfrac{3}{-16}+\dfrac{3}{4}\)
=\(\left(\dfrac{5}{12}+\dfrac{9}{12}\right)-\dfrac{-3}{16}\)
=\(\dfrac{7}{6}-\dfrac{-3}{16}\)
=\(\dfrac{56}{48}-\dfrac{-9}{48}\)=\(\dfrac{65}{48}\)
D.\(\dfrac{5}{15}+\dfrac{4}{-12}+\dfrac{1}{7}-\dfrac{1}{-6}\)
=\(\dfrac{1}{3}+\dfrac{1}{7}+(\dfrac{-2}{6}-\dfrac{-1}{6})\)
=\(\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{-1}{6}\)
=\((\dfrac{1}{3}+\dfrac{-1}{6})+\dfrac{1}{7}\)
=\(\dfrac{1}{6}+\dfrac{1}{7}\)=\(\dfrac{13}{42}\)
Tinh nhanh
a ) 18*76+24*18-150
b ) 147 +230+53+70
c) 7*85+27*7-7*12
d) 58*75+58*50-58*25
e) 2 va3/5-2/5*(5/8-7/12)
f ) 1/3-5/4*4/15
1) Tinh nhanh:
a) 18*76+24*18-150
b) 147+230+53+70
c) 7*85+27*7-7*12
d) 58*75+58*50-58*25
e)2va3/5-2/5*(5/8-7/12)
f) 1/3-5/4*4/15
bài 1:tính
a)\(\left(\dfrac{-7}{15}-\dfrac{27}{70}\right)-\left(\dfrac{8}{15}+\dfrac{43}{70}\right)\)
b)\(\dfrac{3}{7}+\left(\dfrac{-1}{5}+\dfrac{-3}{7}\right)\)
c)\(\left(4-\dfrac{12}{5}\right).\dfrac{25}{8}-\dfrac{2}{5}:\dfrac{-4}{25}\)
d)\(\left(\dfrac{-5}{24}+\dfrac{3}{4}-\dfrac{7}{12}\right):\left(-\dfrac{5}{16}\right)\)
e)\(\dfrac{-5}{7}.\dfrac{2}{11}+\dfrac{-5}{7}.\dfrac{9}{11}\)
g)\(\dfrac{6}{7}+\dfrac{5}{4}:\left(-5\right)-\dfrac{-1}{28}.\left(-2\right)^2\)
Giải:
a)(-7/15-27/70)-(8/15+43/70)
=-7/15-27/70-8/15-43/70
=(-7/15-8/15)+(-27/70-43/70)
=-1+(-1)
=-2
b)3/7+(-1/5+-3/7)
=3/7-1/5+-3/7
=(3/7+-3/7)-1/5
=0-1/5
=-1/5
c)(4-12/5).25/8-2/5:-4/25
=8/5.25/8-(-5/2)
=5+5/2
=15/2
d)(-5/24+3/4-7/12):(-5/16)
=-1/24:(-5/16)
=2/15
e)-5/7.2/11+-5/7.9/11
=-5/7.(2/11+9/11)
=-5/7.1
=-5/7
g)6/7+5/4:(-5)-(-1/28).(-2)2
=6/7+(-1/4)-(-1/28).4
=6/7+(-1/4)-(-1/7)
=6/7-1/4+1/7
=(6/7+1/7)-1/4
=1-1/4
=3/4
Chúc bạn học tốt!
Tim x
50 -2 x ( x +1 )=20
Tinh nhanh
147+230+53+70
7*85+27*7-7*12
58*75+58*50-58*25
Thuc hien phep tinh hop li(neu co the):
1) 69 .113 - 27. 69 + 69 .14 + 31
2) 90 -(22. 25 - 32. 7)
3) 720 - {40.[(120 - 70) :25 + 23]}
4) 2345 - 1000 :[19 - 2(21 - 18)2]
5) (-23) + 13 + (-17) + 57
6) (-123) + |-13| + (-7)
7) - |-33| +(-15)+ 20 - |45 - 40| - 57
quy đồng mẫu
a, 7/30 ; -3/25 ;9/-10
b, 3/7 ; 2/ 5 ; -9/70
c, -5/2 ; 3/-7
d , 8 ; -4/16
e, 5/3 ; -25/30 ; -5/6
14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
14 . 35 . 5 + 10 . 25 . 7 + 20 . 70
= ( 14 . 5 ) . 35 + ( 10 . 7 ) . 25 + 20 . 70
= 70 . 35 + 70 . 25 + 20 . 70
= 70 . ( 35 + 25 + 20 )
= 70 . 80
= 5600
toán lớp 6 phải thay dấu nhân thành dấu chấm nhé! ;3
14 x 35 x 5 + 10 x 25 x 7 + 20 x 70 = 5600
Chúc bn hok tốt!
Tìm x
(160 x 5 -25 x 4) : 7 - 3 * x = 36 x 25 : 9 - 70
Tính Nhanh
2222/333 + 111111/151515 - 2/5
Tìm x
700:7-3*x=36*25:9-70
100-3*x=100-70
100-3*x=30
3*x=70
x=70/3
Câu đầu ko rõ đề lắm nên làm câu 2 ha:
\(\frac{2222}{333}+\frac{111111}{151515}-\frac{2}{5}\)
\(=\frac{2222}{333}+\left(\frac{11}{15}-\frac{6}{15}\right)\)
\(=\frac{2222}{333}+\frac{1}{3}\)
\(=\frac{2222}{333}+\frac{111}{333}=\frac{2333}{333}\)
câu đầu là tính nhanh nha bạn Đình Sang Bùi