Question

If a + b equals to 4 and ab equals to minus 12 find a minus b and a square minus b square

Answer 1

Step-by-step explanation:

a+b = 4

ab = -12

(a-b)^2 = (a+b)^2 - 4ab = 4^2 - 4×(-12) = 16 + 48 = 64

=> a-b = ± 8

a^2 - b^2 = (a+b)×(a-b) = 4×8 or 4×(-8) = ± 32