Question

10x+7y=1
-5x-7y=24
Solving systems of equations by substitution

Answer 1

`10x+7y=1 \\ -5x-7y=24 \\ \\ \hbox{solve the first equation for y:} \\ 10x+7y=1 \ \ \ |-10x \\ 7y=-10x+1 \ \ \ |/ 7 \\ y=(-10x+1)/(7) \\ \\ \hbox{substitute the result for y in the second equation:} \\ -5x-7((-10x+1)/(7))=24 \\ -5x-(-10x+1)=24 \\ -5x+10x-1=24 \\ 5x-1=24 \ \ \ |+1 \\ 5x=25 \ \ \ |/ 5 \\ x=5 \\ \\ y=(-10x+1)/(7)=(-10 * 5+1)/(7)=(-50+1)/(7)=(-49)/(7)=-7 \\ \\ \boxed{(x,y)=(5,-7)}`