Question

How do you solve the system 2x + 7y = 3 and x = 1 - 4y?

Answer 1

x = 5 , y = -1

Explanation:

Since one of the equations gives x in terms of y , ie x = 1 - 4y

Then this can be substituted directly into the other equation.

→ 2(1 - 4y) + 7y = 3 → 2 - 8y + 7y = 3 → -y = 1 → y = -1

now, substitute y = -1 into x = 1 - 4y , to obtain x

→ x = 1 - 4(-1) = 1 + 4 = 5

Thus solution is (5 , -1 )