Ответ:
- \(400-m^2=(20-m)(20+m)\).
- \(4x^2-25=(2x-5)(2x+5)\).
- \(\frac79t^2-1=\left(\frac{\sqrt7}{3}t-1\right)\left(\frac{\sqrt7}{3}t+1\right)\).
- \(16a^4-81=(4a^2-9)(4a^2+9)=(2a-3)(2a+3)(4a^2+9)\).
- \((x+1)^2-16=(x-3)(x+5)\).
- \(a^2-12a+36=(a-6)^2\).
- \(16m^2+24mn+9n^2=(4m+3n)^2\).
