Grade 9 · Algebra & functions

Systems of equations practice

Systems of equations 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 20 systems of equations problems our math games drill.

CCSS HSA.REI.C.620 questions in the bank
Sample questions

Try 8 for free

Question 1easy

Solve the system: {x+y=5 xy=1\begin{cases} x + y = 5 \ x - y = -1 \end{cases}
What is the value of
xx?

Add the equations: 2x=42x = 4, so x=2x = 2.

Question 2easy

If y=x+3y = x + 3 and x+y=9x + y = 9, what is the value of xx?

Substitute: x+(x+3)=9x + (x + 3) = 9, so 2x=62x = 6 and x=3x = 3.

Question 3easy

Solve the system: {x+y=3 xy=5\begin{cases} x + y = 3 \ x - y = -5 \end{cases}
What is the value of
xx?

Add the equations: 2x=22x = -2, so x=1x = -1.

Question 4easy

Two lines satisfy y=3xy = 3x and y=x+10y = x + 10. What is the xx-value of the solution?

Set the expressions equal: 3x=x+103x = x + 10, so 2x=102x = 10 and x=5x = 5.

Question 5easy

Solve the system: {x+y=3 xy=7\begin{cases} x + y = 3 \ x - y = 7 \end{cases}
What is the value of
xx?

Add the equations: 2x=102x = 10, so x=5x = 5.

Question 6easy

Solve the system: {x+y=4 xy=2\begin{cases} x + y = 4 \ x - y = 2 \end{cases}
What is the value of
xx?

Add the equations: 2x=62x = 6, so x=3x = 3.

Question 7easy

Solve the system: {x+y=7 xy=7\begin{cases} x + y = 7 \ x - y = -7 \end{cases}
What is the value of
xx?

Add the equations: 2x=02x = 0, so x=0x = 0.

Question 8easy

Solve the system: {x+y=5 xy=3\begin{cases} x + y = -5 \ x - y = -3 \end{cases}
What is the value of
xx?

Add the equations: 2x=82x = -8, so x=4x = -4.

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