Question

1. Which of the following equations shows how substitution can be used to solve the following syster

y = 2x + 3
2x + 5y = 3

2x + 5y = 2x + 3
2x + 5(2x + 3) = 3
2(2x + 3) +5y = 3
y = 3

Answer 1

It would be the second option, 2x+5(2x+3)=3. Solving a system of equations by substitution is where you solve for one of the equations and plug it into the other. The top equations shows what y is equal to. And they plugged that equation in for y in the second.