Exercise 4.2 (PCTB)

1. Factorize each of the following expressions: (i) $4x^4 + 81y^4$ $$(2x^2)^2 + (9y^2)^2 + 2(2x^2)(9y^2) – 2(2x^2)(9y^2)$$ $$(2x^2 + 9y^2)^2 – 36x^2y^2$$ $$(2x^2 + 9y^2)^2 – (6xy)^2$$ $$(2x^2 + 9y^2 + 6xy)(2x^2 + 9y^2 – 6xy)$$ (ii) $a^4 + 64b^4$ $$(a^2)^2 + (8b^2)^2 + 2(a^2)(8b^2) – 2(a^2)(8b^2)$$ \[(a^2 + 8b^2)^2…