✔ 最佳答案
1) Factorize the following expressions:
p^2 - q^2 + 4p + 4q <--grouping terms
=(p+q)(p-q)+4(p+q) <---a^2-b^2=(a+b)(a-b)
=(p+q)(p-q+4)
2) Factorize the following expressions:
a^2 - b^2 + bc - ac <--Grouping terms
=(a+b)(a-b)+c(b-a) <--a^2-b^2=(a+b)(a-b)
=(a+b)(a-b)-c(a-b)
=(a-b)(a+b-c)
3) Factorize the following expressions:
75(m - 3n)^2 - 27(2m - 5n)^2
= 3[25(m-3n)^2-9(2m-5n)^2] <---Find common factor
=3[5^2(m-3n)^2-3^2(2m-5n)^2]
=3{[5(m-3n)]^2-[3(2m-5n)]^2}
=3(5m-15n)^2-(6m-15n)^2 <---a^2-b^2=(a+b)(a-b)
=3(5m-15n+6m-15n)(5m-15n-6m+15n)
=3(11m-30n)(-m)
=-3m(11m-30n)
4) Factorize the following expressions:
3u^2 - 12v^2 - 6u + 12v
=3(u^2-4v^2-2u+4v) <----Find common factor
=3[u^2-(2v)^2-2u+4v] <----a^2-b^2=(a+b)(a-b)
=3[(u+2v)(u-2v)-2(u+2v)]
=3(u+2v)(u-2v-2)