Question

Multiply: (8a + 5b) (8a - 5b).
A.16a2 + 25b2
B. 64a2 - 25b2
C.16a2 - 10ab + 25b2
D. 64a2 - 40ab + 25b

Answer 1

\[64a ^{2 }- 25b ^{2}\]

Answer 2

64a^2-25b^2

Answer 3

B..64a2-25b2

Answer 4

Thanks

Answer 5

Use difference of 2 squares: (a-b)(a+b) = a^2 -b^2
put a = 8a and b= 5b into the formula , you'll get
(8a + 5b) (8a - 5b) = (8a)^2 - (5b)^2 = 64a^2 - 25b^2