Question

Find two values of n that satisfy the equation.
n(n – 1) = 90
a. 9 and –10
b. 9 and –9
c. 10 and –10
d. 10 and –9

i just need the answer

Answer 1

n^2 -n-90=0

Answer 2

to simplify that we need a and b so that ab=90 and a+b=-1

Answer 3

so a+b=-1 is right but a*b=90 not is because a*b = - 90

hope will help you