If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to x from the second equation is substituted into the first equation.

3x + 2y = –21
x – 3y = 4

3(3y + 4) + 2y = –21
3(–3y + 4) + 2y = –21
3x + 2(3y + 4) = –21
3x + 2(–3y + 4) = –21

Question

If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to x from the second equation is substituted into the first equation.

3x + 2y = –21
x – 3y = 4

3(3y + 4) + 2y = –21
    3(–3y + 4) + 2y = –21
    3x + 2(3y + 4) = –21
    3x + 2(–3y + 4) = –21

jhonyy9 · Answer

x=3y+4 so the first is right 3(3y+4)+2y= -21