Find the products: (i)(5-2x)(3+x) (ii)(x+7y)(7x-y) (iii)(a²+b)(a+b²) (iv)(p²-q²)(2p+q)

(i)(5-2x)(3+x)=5(3+x)-2x(3+x)=15+5x-6x-2x²=15-x-2x²
(ii)(x+7y)(7x-y)=x(7x-y)+7y(7x-y)=7x²-xy+49xy-7y²=7x²+48xy-7y²
(iii)(a²+b)(a+b²)=a²(a+b²)+b(a+b²)=a³+a²b²+ab+b³
(iv)(p²-q²)(2p+q)=p²(2p+q)-q²(2p+q)=2p³+p²q-2pq²-q³