Jawabanmu

2014-03-01T17:20:46+07:00
(2x-5y) (2x-5y)
4x²-10y-10y+25y²
4x²-20y+25y²
2014-03-01T17:51:34+07:00
(2x-5y)²= 1.4x² + 2.x²y + 1.-25y²
          = 4x² + 2x²y - 25y²