Question

Câu hỏi: Tìm x, biết:

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

b) 3 - ( 17 - x ) = 289 -  ( 36 + 289 )

Giúp mik nha, mik đang cần gấp. Mik cảm ơn mng trc !

Answer 1

Mình không viết lại đề nhé

a) -12x + 60 + 21 - 7x = 5

-19x = 5 - 71

-19x = -76

x = 4

b) 3 - 17 + x = 289 - 36 - 289

x = -22

Answer 2

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

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

\(=>-19x=5-60-21=-76\)

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

\(b,3-\left(17-x\right)=289-\left(36+289\right)\)

\(=>3-17+x=-36\)

\(=>x=-36+17-3=-22\)

Answer 3

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

<=> -12x+60+21-7x=5

<=> 9+53x=5

<=> 53x=-4

<=> x=\(\frac{-4}{53}\)

b) 3-(17-x)=289-(36+289)

<=> 3-17+x=289-36-289

<=> -14+x=-36

<=> x=-22

Answer 4

câu b neh

3 - ( 17 - x ) = 289 -  ( 36 + 289 )

3-17+x=289-36-289

3-17+x=-36

17+x=3-(-36)

17+x=39

=>...... tự làm

Answer 5

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

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

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

\(-19x=-76\Leftrightarrow x=4\)

\(b,3-\left(17-x\right)=289-\left(36+289\right)\)

\(3-\left(17-x\right)=289-325\)

\(3-\left(17-x\right)=-36\)

\(17-x=39\)

\(x=-22\)

Answer 6

a)x=4

B)x=-22

Answer 7

a)-12(x - 5)+7(3 - x) = 5

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

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

=>-12x - 7x + 81 = 5

=>-12x - 7x = -76

=>(-12 - 7)x = -76

=>-19 . x = -76

=>x = -76 : (-19)

=>x = 4

    Vậy ....