Solve for z.

42 = - 7 (z - 3)

z = ?

To solve for z you need to get it by itself and have the other half of the equal sign simplified.

42=-7 (z-3)

42=-7z+21 (you would distribute the - 7 through the parentheses.)

21=-7z (you would then subtract 21 from both sides)

-3=z (last your would divide - 7 to both sides to get z by itself)

z=-3

You divide by - 7 on both sides then add three to both sides and the answer is - 3