Answer y = -2
Step 1.
In order to make an equation with 1 variable, substitute the right side of the first equation for x in the second equation for 3x + 5y = 20. In the example all instances of x in the second equation will be replaced by 10.
Rewrite the x so it will be 3 · 10.
3 · 10 + 5y = 20
Step 2.
Multiply 3 by 10.
3 × 10 = 30
Step 3.
Subtract 30 from both sides.
30 + 5y - 30 = 20 - 30
Step 4.
Simplify.
5y = -10
Step 5.
Divide both sides by 5.
1. Divide the numbers.
5 ÷ 5 = 1
= y
2. Simplify.
Apply the fraction rule.
3. Divide.
10 ÷ 5 = 2
Y = -2