Answer
$$x=7$$ $$y=1$$
Work Step by Step
Equation 1: $x + 9y = 16$
Equation 2: $3x - 8y = 13$
Solve the system using substitution method.
Using equation 1, subtract $9y$ from both sides:
$$x + 9y -9y= 16-9y$$ $$x= 16-9y$$
Substitute this equation to equation 2:
$$3( 16-9y) - 8y = 13$$ $$48-27y-8y=13$$ $$48-35y=13$$
Subtract $48$ from both sides:
$$48-48-35y=13-48$$ $$-35y=-35$$
Divide both sides by $-35$:
$$\frac{-35y}{-35}=\frac{-35}{-35}$$ $$y=1$$
Substitute this value of $y$ to equation 1:
$$x+9(1)=16$$ $$x+9=16$$
Subtract $9$ from both sides:
$$x+9-9=16-9$$ $$x=7$$
Use equation 2 to check:
$$3(7)-8(1)=13$$ $$21-8=13$$ $$13=13$$
