Question

Find missing variable and check: -3(x-6)+4(x+1)=7x-14

Answer 1

We need to solve the equation to find x

$-3(x-6)+4(x+1)=7x-14$

We will simplify the left side by multiply each bracket by the number before it

-3(x - 6) = -3(x) + -3(-6) = -3x + 18

4(x + 1) = 4(x) + 4(1) = 4x + 4

Now put them on the left side

$-3x+18+4x+4=7x-14$

Add the like terms on the left side

$\begin{gathered} (-3x+4x)+(18+4)=7x-14 \\ x+22=7x-14 \end{gathered}$

Now we will collect x on the right side and the numbers on the left side

Subtract x from both sides

$\begin{gathered} x-x+22=7x-x-14 \\ 22=6x-14 \end{gathered}$

Add 14 to both sides

$\begin{gathered} 22+14=6x-14+14 \\ 36=6x \end{gathered}$

Divide both sides by 6 to find x

$\begin{gathered} \frac{36}{6}=\frac{6x}{6} \\ 6=x \end{gathered}$

The value of x is 6