# How do you solve 13= \frac { 4- b } { 3}?

May 29, 2018

$b = - 35$

#### Explanation:

As per the question, we have

$13 = \frac{4 - b}{3}$

$13$ x $3 = \frac{4 - b}{3}$ x $3$ ... [Multiplying 3 on both the sides]

$\therefore 39 = \frac{4 - b}{\cancel{3}}$ x $\cancel{3}$

$\therefore 39 = 4 - b$

$\therefore 39 - 4 = 4 - 4 - b$ ... [Subtracting 4 from both the sides]

$\therefore 35 = \cancel{4} \cancel{-} 4 - b$

$\therefore - b = 35$

$\therefore b = - 35$

May 29, 2018

$b = - 35$

#### Explanation:

$\text{multiply both sides by 3}$

$3 \times 13 = \cancel{3} \times \frac{4 - b}{\cancel{3}}$

$39 = 4 - b$

$\text{subtract 4 from both sides}$

$39 - 4 = \cancel{4} \cancel{- 4} - b$

$35 = - b \text{ or } b = - 35$

$\textcolor{b l u e}{\text{As a check}}$

Substitute this value into the right side of the equation and if equal to the left side then it is the solution.

$\frac{4 - \left(- 35\right)}{3} = \frac{4 + 35}{3} = \frac{39}{3} = 13$

$b = - 35 \text{ is the solution}$

May 29, 2018

$b = - 35$

#### Explanation:

Multiply by $3$:

$\left(13 \times 3\right) = \frac{4 - b}{\cancel{3}}$

$\Rightarrow 39 = 4 - b$

Bring the $b$ to the other side to make is positive:

$b + 39 = 4$

$\Rightarrow b = - 35$