Algebra-1

To solve a system of equations by substitution, follow these steps:

Solve one equation for one variable: Choose one of the equations and solve it for one of the variables (e.g., solve for x in terms of y or solve for y in terms of x).
(Since the question already uses a constant to represent y, then skip it.)

Substitute into the other equation: Substitute the expression from step 1 into the other equation. This will result in an equation with only one variable.
(In this question, we put the constant of y into the other equation so ...