Easy Substitution System

What is the solution to the following system?

^{y = 5}

^{-3x + 4y = 8}

• (5, 7)

• (4, 5)

• (-3, 5)

• (-4, -20)

What is the solution to the following system?

^{x = 4y}

^{x - 4y = 0}

• (0, 0)

• no solutions

• infinite solutions

• (4, 0)

What is the solution to the following system?

^{x = -2y}

^{3x + 4y = -8}

• (-2, -8)

• (4, 3)

• (-2, 4)

• (-8, 4)

Which option shows the CORRECT substitution for this system?

Why does substitution help us solve a system of equations?

• It changes one variable to an expression using the other variable, so we can solve an equation that only has one variable at a time.

• It creates a problem with fewer steps.

• It puts both equations in slope-intercept form for easy graphing.

TRUE or FALSE:

When both equations have the same variable isolated

(both y = or both x = ),

substituting the first into the second ends up looking like

you just set the two equal to each other.

• TRUE

• FALSE

Which option shows the CORRECT substitution for this system?

Which option shows the CORRECT substitution for this system?

Which option shows the CORRECT substitution for this system?

Which option shows the CORRECT substitution for this system?