Systems by simple substitution. Game on.

Systems by simple substitution is a grade 9 math skill aligned to Common Core standard HSA.REI.C.6: solve systems of linear equations exactly and approximately, focusing on pairs of linear equations in two variables. Below are 8 practice questions with answers and step-by-step explanations, drawn from the 10 systems by simple substitution problems our math games drill.

CCSS HSA.REI.C.610 questions in the bank
Kickoff

8 plays. No signup.

Warm-upeasy

{y=2x5 y=7\begin{cases} y = 2x - 5 \ y = 7 \end{cases}
What is the solution
(x,y)(x, y) to the given system of equations?

Substitute y=7y = 7 into y=2x5y = 2x - 5: 7=2x57 = 2x - 5, so 12=2x12 = 2x and x=6x = 6. The solution is (6,7)(6, 7).

Mid-gameeasy

{y=2x+10 y=4\begin{cases} y = -2x + 10 \ y = 4 \end{cases}
What is the solution
(x,y)(x, y) to the given system of equations?

Substitute y=4y = 4 into y=2x+10y = -2x + 10: 4=2x+104 = -2x + 10, so 6=2x-6 = -2x and x=3x = 3. The solution is (3,4)(3, 4).

Mid-gameeasy

{y=5x1 y=14\begin{cases} y = 5x - 1 \ y = 14 \end{cases}
What is the solution
(x,y)(x, y) to the given system of equations?

Substitute y=14y = 14 into y=5x1y = 5x - 1: 14=5x114 = 5x - 1, so 15=5x15 = 5x and x=3x = 3. The solution is (3,14)(3, 14).

Mid-gameeasy

{y=2x+9 y=3\begin{cases} y = 2x + 9 \ y = 3 \end{cases}
What is the solution
(x,y)(x, y) to the given system of equations?

Substitute y=3y = 3 into y=2x+9y = 2x + 9: 3=2x+93 = 2x + 9, so 6=2x-6 = 2x and x=3x = -3. The solution is (3,3)(-3, 3).

Mid-gameeasy

{y=3x4 y=x\begin{cases} y = 3x - 4 \ y = x \end{cases}
What is the solution
(x,y)(x, y) to the given system of equations?

Set the expressions for yy equal: 3x4=x3x - 4 = x, so 2x=42x = 4 and x=2x = 2. Then y=2y = 2. The solution is (2,2)(2, 2).

Mid-gameeasy

{y=x+8 y=3x\begin{cases} y = -x + 8 \ y = 3x \end{cases}
What is the solution
(x,y)(x, y) to the given system of equations?

Set the expressions for yy equal: x+8=3x-x + 8 = 3x, so 8=4x8 = 4x and x=2x = 2. Then y=3(2)=6y = 3(2) = 6. The solution is (2,6)(2, 6).

Mid-gameeasy

{y=4x+5 y=x\begin{cases} y = 4x + 5 \ y = -x \end{cases}
What is the solution
(x,y)(x, y) to the given system of equations?

Set the expressions for yy equal: 4x+5=x4x + 5 = -x, so 5x=55x = -5 and x=1x = -1. Then y=(1)=1y = -(-1) = 1. The solution is (1,1)(-1, 1).

Buzzer beatereasy

{y=6x2 y=4x\begin{cases} y = 6x - 2 \ y = 4x \end{cases}
What is the solution
(x,y)(x, y) to the given system of equations?

Set the expressions for yy equal: 6x2=4x6x - 2 = 4x, so 2x=22x = 2 and x=1x = 1. Then y=4(1)=4y = 4(1) = 4. The solution is (1,4)(1, 4).

Drill it inside a game.

The free placement test finds your level, then every match serves systems by simple substitution questions at exactly the right difficulty.