Объяснение:
а)7m²-7n²= 7(m²-n²)=7(m-n)(m+n)
б) x³-3x²-4x+12= x²(x-3)-4(x-3)=(x-3)(x²-4)=(x-3)(x²-2²)=(x-3)(x-2)(x+2)
в)9x²+6x+1= (3x)²+2·3x·1+1²=(3x+1)²
г) а³-125= a³-5³=(a-5)(a²+5·a+5²)=(a-5)(a²+5·a+25)
д)64а⁴-аb³= a(64a³-b³)=a((4a)³-b³)=a(4a-b)((4a)²+4a·b+b²)=a(4a-b)(16a²+4ab+b²)
э)x⁴-625=x⁴-5⁴=(x²)²-(5²)²=(x²-5²)(x²+5²)=(x-5)(x+5)(x²+25)
