Question

The equation x2 – 1x – 90 = 0 has solutions {a, b}. What is a + b?

Answer 1

90=0 so therefore the answer is right there 100%

Answer 2

a + b = 1

Explanation:

We have the roots of ax²+bx+c = 0 as
`(-b\pm √(b^2-4ac))/(2a)`.

Sum of roots
`=(-b+√(b^2-4ac))/(2a)+(-b-√(b^2-4ac))/(2a)=-(b)/(a)`

Here equation is x²-x-90 = 0

a = 1, b = -1 and c = -90

Sum of roots = a + b
`=-(b)/(a)=-(-1)/(1)=1`

a + b = 1