Răspuns:
7)16a²-25b²=(4a+5b)(4a-5b)
0.09x²-0.01y²=(0.3x-0.1y)(0.3x+0.1y)
8)48=6²+2²+2²+2²
28=4²+2²+2²+2²
9)60=8²-2²
44=7²-2²-1²