Question

To solve the system of equations below, Maria isolated the variable y in the first equation and then substituted it into the second equation. What was the resulting equation? 3y = 12x x^2 +y = 18

Answer 1

x^2 +4x = 18

Explanation:

The variable y is isolated in the first equation by dividing both sides by the coefficient of y:

3y = 12x . . . . . . given

3y/3 = 12x/3 . . . . . divide by the coefficient of y

y = 4x . . . . . . . simplify

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This expression (4x) is put in place of y when substitution is used.

x^2 +y = 18 . . . . given

x^2 +4x = 18 . . . . . with 4x substituted for y