Question
one less than a positive number times three more than that number is 32. Find the number
Answers
Reiny
let the number be x
(x-1)(x+3) = 32
x^2 + 2x - 3 - 32 = 0
x^2 + 2x - 35 = 0
(x+7)(x-5) = 0
x = -7 or x = 5, but the number was to be positive, so
the number is 5
check:
4(8) = 32
looks fine.
(x-1)(x+3) = 32
x^2 + 2x - 3 - 32 = 0
x^2 + 2x - 35 = 0
(x+7)(x-5) = 0
x = -7 or x = 5, but the number was to be positive, so
the number is 5
check:
4(8) = 32
looks fine.