Question

Tìm x biết

80-3(x-7)=20

4(x-1)+5=25

Answer 1

80 - 3 ( x - 7 ) = 20

<=> 3 ( x - 7 ) = 60

<=> x - 7 = 20

<=> x = 27

4 ( x - 1 ) + 5 = 25

<=> 4 ( x - 1 ) = 20

<=> x - 1 = 5

<=> x = 6

Answer 2

\(\text{Giải:}\)

\(80-3\left(x-7\right)=20\)

\(3\left(x-7\right)=80-20\)

\(3\left(x-7\right)=60\)

\(x-7=60:3\)

\(x-7=20\)

\(x=20+7\)

\(x=27\)

\(\text{Vậy x = 27}\)

\(4\left(x-1\right)+5=25\)

\(4\left(x-1\right)=25-5\)

\(4\left(x-1\right)=20\)

\(x-1=20:4\)

\(x-1=5\)

\(x=5+1\)

\(x=6\)

\(\text{Vậy x = 6}\)

\(\text{Học tốt!!!}\)

Answer 3

1) \(80-3\left(x-7\right)=20\)

\(\Leftrightarrow80-3x+21=20\)

\(\Leftrightarrow3x=81\)

\(\Rightarrow x=27\)

2) \(4\left(x-1\right)+5=25\)

\(\Leftrightarrow4x-4+5=25\)

\(\Leftrightarrow4x=24\)

\(\Rightarrow x=6\)