# How do you solve the system of equations:y=4, 3/5x+y=8?

## When getting rid of the fraction, do you do this: 3/5x+y=8 5 5 3x+y=40 or: 3x+5y=40?

Jun 7, 2018

$\left(x , y\right) = \left(\frac{20}{3} , 4\right)$

#### Explanation:

First, to answer your equation, multiplying the whole equation ("getting rid of the fraction" $\frac{3}{5} x + y = 8$ by 5 would give you $3 x + 5 y = 40$

Now, for solving the system of equations:
$3 x + 5 y = 40$
$y = 4$
Those are our two equations.
We can plug $y = 4$ (which is given) into the other equation to solve for x.
$3 x + 5 \left(4\right) = 40$
$3 x + 20 = 40$
$3 x = 20$
$x = \frac{20}{3}$
Because the y-value was given to us, we can conclude that $\left(x , y\right) = \left(\frac{20}{3} , 4\right)$