Question

How many solutions are there to the equation n^2-13n=-40

Answer 1

It has 2 real solutions which are 5 and 8

Answer 2

n = 5

n = 8

Explanation:

n^2 - 13n = -40

Equate everything to zero

n^2 - 13n + 40 = 0

Factorise

(n - 5)(n - 8) = 0

Either

n - 5 = 0

Add 5 to both sides

n - 5 + 5 = 0 + 5

n = 5

Or

n - 8 = 0

Add 8 to both sides

n - 8 + 8 = 0 + 8

n = 8

n = 5 or

n = 8

It has two real solutions