Question

tìm x biết:

a)-12(x-5)+7(3-x)=5

b)30(x+2)-6(x-5)-24=100

Answer 1

a, => -12x+60+21-7x=5

=> 71-19x=5

=> 19x = 71-5 = 66

=> x = 66 : 19 = 4

b, => 30x+60-6x+30-24=100

=> 24x+76 = 100

=> 24x = 100-76 = 24

=> x = 24 : 24 = 1

Tk mk nha

Answer 2

bài này dễ lắm ....

dù mình ko làm dc

Answer 3

a,        -12x-(-60)+21-7x=5

-19x+81=5

-19x=5-81

-19x=-76

x=-4

b,          30(x+2)-6(x-5)-24=100

30x+60-6x+30-24=100

36x+76=100

36x=34

x=34/36

Answer 4

a,-12(x-5)+7(3-x)=5

    -12x+60+21-7x=5

     81-19x =5

19x=76

=>x=4

b,30(x+2)-6(x-5)-24=100

30x+60-6x+30-24=100

24x+66=100

24x=34=>x=34/24=17/12

Answer 5

a, => -12x+60+21-7x=5
=> 71-19x=5
=> 19x = 71-5 = 66
=> x = 66 : 19 = 4
b, => 30x+60-6x+30-24=100
=> 24x+76 = 100
=> 24x = 100-76 = 24
=> x = 24 : 24 = 1
Tk mk nha $_$

Answer 6

a, x = - 4

b x =  1

Answer 7

\(a,-12\left(x-5\right)+7\left(3-x\right)=5\)

\(\Leftrightarrow-12x+60+21-7x=5\)

\(\Leftrightarrow19x=71-5=66\)

\(\Leftrightarrow x=66:19=4\)

Answer 8

\(a,-12\left(x-5\right)+7\left(3-x\right)=5\)

\(=>-12x+60+21-7x=5\)

\(=>-19x=5-81=-76\)

\(=>x=\frac{-76}{-19}=4\)

\(b,30.\left(x+2\right)-6.\left(x-5\right)-24=100\)

\(=>30x+60-6x+30-24=100\)

\(=>24x=100+24-30-60=124-90=34\)

\(=>x=\frac{34}{24}=\frac{17}{12}\)