Question

solve the following using identities
a) (0 7a -0.3b)^2

b) ( 2.5a + 1.4b) (2.5a - 1.4b)​

Answer 1

what is that 0.7 or 7?

a. using (a - b)^2 formula

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

b. using a^2 - b^2 formula

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

Answer 2

Answer:

a) (4.9a-.42ab +.9b)

b) Use identities (a^2-b^2)=(a+b)(a-b).