Question

6. If x*x + 2x - 35 = 0,
then x = ?

Answer 1

Substitute in 5 for x and check the math.

Answer 2

why 5?

Answer 3

5*5 + 2(5)-35=0
25+10-35=0
35-35=0
0=0

Answer 4

\[ax^2+bx+c=0\]\[\qquad\downarrow\]\[x_{1,2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}\]