Jawabanmu

2014-08-26T21:11:21+07:00
A. (x+5) x (5x-1) = 5x²-1x+25x-5
= 5x²-24x-5
b. (7-2x) x (2x-7) = 14x-49-4x²+14x
= 28x-49-4x²