How do you solve and check your solution given -0.4y=2?

Oct 2, 2017

$y = - 5$

Explanation:

We know that $- 0.4 y = 2$
We multiply both sides by $10$:

$- 0.4 y \textcolor{b l u e}{\cdot} \textcolor{b l u e}{10} = 2 \textcolor{b l u e}{\cdot} \textcolor{b l u e}{10}$
Simplify:
$- 4 y = 20$
Divide both sides by $- 4$

$\frac{- 4 y}{- 4} = \frac{20}{- 4}$
Simplify:
$y = - 5$

Let's check.

$y = - 5$

$- 0.4 y = 2$

$- 0.4 \cdot y = 2$

$- 0.4 \cdot - 5 = 2$

The equation is true.
So, the answer is $y = - 5$.