Twice the square of a certain whole number added to 3 time the number makes 90.
2 answers
n = 6
2x^2 + 3x = 90
2x^2 + 3x - 90 = 0
(x - 6)(2x + 15) = 0
x = 6 or x = -15/2
your number is either 6 or -7.5
2x^2 + 3x - 90 = 0
(x - 6)(2x + 15) = 0
x = 6 or x = -15/2
your number is either 6 or -7.5