Question

Hector solves and equation by subtracting 8 from both sides of the equation. Then he multiples both sides of the equation by 3. The result is m=15. What was the original equation? How do you know?

Answer 1

Given:

The result is $m=15$.

To find:

The original equation.

Solution:

We need to apply the opposite operations from bottom to top in the resultant equation to get the original equation.

It means opposite operation of last operation will be applied first.

We have,

$m=15$

Divide both sides by 3.

$\dfrac{m}{3}=5$

Add 8 on both sides.

$\dfrac{m}{3}+8=5+8$

$\dfrac{m}{3}+8=13$

Therefore, the original equation is $\dfrac{m}{3}+8=13$.