# How do you solve a/40 = 3/10?

Feb 15, 2016

$a = 12$

:)

#### Explanation:

Since $\frac{a}{b} = \frac{c}{d}$,

we can use an algebraic technique, to get the value of $a$, by isolation and using the golden rule of algebra, "Balancing the equation"

$\frac{a}{40} = \frac{3}{10}$

to isolate $a$, we must eliminate $40$ in the left side of the equation by multiplying it by $40$, the golden rule of algebra states that whatever you do in a side of an equation is you also must do it in the other side to keep the equation balanced.

$\left(40\right) \frac{a}{40} = \frac{3}{10} \left(40\right)$

$\frac{\cancel{40} a}{\cancel{40}} = \frac{\left(40\right) \left(3\right)}{10}$

$a = \frac{120}{10}$, we can still simplify the answer giving,

$a = 12$