
Daniel-Joseph K. answered 04/19/13
Versatile math tutor for college and high school
Solve for y in first equation
4x-2=y
Substitute this for y in the second equation which becomes:
9x-2(4x-2)=7
9x-8x+4=7
x+4=7
x=3
Plug 3 for x into first equation.
4(3)-2=y=10
Confirm by second equation
9(3)-2(10)=27-20=7