How do you solve 7/(b+5)=10/5?

Oct 16, 2016

$b = - \frac{3}{5}$

Explanation:

Given:$\text{ } \frac{7}{b + 5} = \frac{10}{5}$

Turn $\underline{\text{everything}}$ upside down so that $b$ is in the numerator (top).

$\frac{b + 5}{7} = \frac{5}{10}$

But $\frac{5}{10} \equiv \frac{1}{2}$

$\frac{b + 5}{7} = \frac{1}{2}$

Multiply both sides by 7

$\frac{7}{7} \times \left(b + 5\right) = 7 \times \frac{1}{2}$

$b + 5 = \frac{7}{2}$

Subtract 5 from both sides

$b = \frac{7}{2} - 5$

$b = \frac{7 - 10}{5}$

$b = - \frac{3}{5}$