Question

expand using formulae is (1.5a+2.5b)

Answer 1

(1.5a)2+(2.5b)2+2(1.5a)(2.5b)
2.25a2+6.25b2+0.75ab

Answer 2

(a+b)^2 = a^2+2ab+b^2

(1.5a+2.5b)^2 = (1.5a)^2 + 2(1.5a)(2.5b) + (2.5b)^2

=2.25a^2 + 3a(2.5b) + 6.25

= 2.25a^2 + 7.5ab + 6.25