Question

tìm x biết 7(x-3)+8(x-2)=5

Answer 1

\(7\left(x-3\right)+8\left(x-2\right)=5\\ \Rightarrow7x-21+8x-16=5\\ \Rightarrow15x-37=5\\ \Rightarrow15x=42\\ \Rightarrow x=2,8\)

Answer 2

    7( x - 3 ) + 8 ( x - 2 ) = 5

⇔ 7x - 21 + 8x - 16 - 5 = 0

⇔                     7x + 8x = 16 + 5 + 21

⇔                           15x = 42

⇔                               x = 2,8

 

 

Answer 3

Ta có: \(7\left(x-3\right)+8\left(x-2\right)=5\)

\(\Leftrightarrow7x-21+8x-16=5\)

\(\Leftrightarrow15x=42\)

hay \(x=\dfrac{14}{5}\)