Problema Solution
If a number is added to two times its square the result is thirty-six. Find all such numbers.
Answer provided by our tutors
let 'x' be a a number such that
x + 2*x^2 = 36
2*x^2 + x - 36 = 0
we will find x by solving the quadratic equation.
the equation has 2 real solutions
x1 = -4.5
x2 = 4
indeed
- 4.5 + 2*(-4.5)^2 = 36
4 + 2*4^2 = 36
All such numbers are -4.5 and 4.