x + 4y = 4
-5x + 3y = 3
Solving by Substitution
First, let's use one of these equations and simplify for the equation of a value. I think x will be a good one to solve first because it looks easy to simplify. Let's begin:
x + 4y = 4
Subtract 4y from both sides to get an equation for x. You should now have:
x = -4y + 4
This will be our x value that we'll be substituting in the second equation. Let's plug this term in:
-5x + 3y = 3
#-5(-4y + 4) + 3y = 3
Distribute. -5y * -4y becomes 20y because two positives make a negative, and -5 * 4 will become -20 because only one negative is present.
20y - 20 + 3y = 3
Combine like terms.
23y - 20 = 3
Now, it's a two-step equation. Add 20 to both sides to cancel out -20 in order to get the division step. You should now have:
23y = 23
Divide by 23 to isolate for y.
y = 1
Now knowing what y is, return to your simplified equation for the value of x and substitute the value of y for y:
x = -4y + 4
x = -4(1) + 4
x = -4 + 4
x = 0
