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?

1 Answer
Jun 7, 2018

(x,y) = (20/3, 4)

Explanation:

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

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