Ответ:

1)

a)9p^2-4=3^2p^2-2^2=(3p)^2-2^2=(3p-2)*(3p+2)

б)1-25x^2=1^2-5^2x^2=1^2-(5x)^2=(1-5x)*(1+5x)

в)36-49a^2=6^2-7^2a^2=6^2-(7a)^2=(6-7a)*(6+7a)

2)

а)1/36-c^2=1/36(1-36c^2)=1/36(1-6c)*(1+6c)

б)-25/36+y^2=y^2-25/36=1/36(36y^2-25)=1/36(6y-5)*(6y+5)

в)25p^2-4/121=1/121(3025p^2-4)=1/121(55p-2)*(55p+2)

3)

а)4x^2-y^2=2^2x^2-y^2=(2x)^2-y=(2x-y)*(2x+y)

б)16a^2-b^2=4^2a^2-b=(4a)^2-b^2=(4a-b)*(4a+b)

в)81k^2-c^2=9^2k^2-c^2=(9k)^2-c=(9k-c)*(9k+c)