Question

If a+b=4 and ab= -12,find, a-b

Answer 1

Hey mate hope it helps you...

a = 4-b

ab = -12

(4-b)b = -12

-12 = 4b - b²

b² - 4b - 12 = 0

b² + 2b - 6b - 12 = 0

b(b+2) - 6(b+2) = 0

b = 6 or -2

If b = 6 ; a = -2

If b = -2; a = 6