Răspuns:
9(2x+5)²-4(4x+3)²=(6x+15-8x-6)(6x+15+8x+6)=(-2x+9)(14x+21)=(-2x+9)7(2x+3)=7(-2x+9)(2x+3)
Răspuns:
Explicație pas cu pas:
9×(2x+5)²-4×(4x+3)²=3²×(2x+5)²-2²×(4x+3)²=[3×(2x+5)]²-[2×(4x+3)]²=
=[3×(2x+5)-2×(4x+3)]·[3×(2x+5)+2×(4x+3)]=(6x+15-8x-6)·(6x+15+8x+6)=
=(9-2x)(21+14x)