I'm assuming you want us to solve for the unknown variable z

Combine like terms on the right side

Use the distributive property on the left side

Add both sides by 20 to cancel out the "-20" on the left side

Divide both sides by 10

That is the value of the known variable, z, in this equation. Let me know if you need any clarifications, thanks!
~ Padoru
replace the numbers given for x & y so
the equation becomes 3*(-3) + 2*(-4) =
3*-3 = -9
2*-4 = -8
-9 + -8 = -17
The answer is 25, leave a like (:
Add 9 to both sides to get 4n=0 so n=0