Question

Consider the following quadratic equation: y = 5x 2 + 15x − 50.

What are the coordinates of the point(s) where the graph of the function crosses the x-axis?

(a) (0, −2) and (0, 4)

(b) (0, 2) and (0, 4)

(c) (2, 0) and (−5, 0)

(d) (2, 0) and (4, 0)

Answer 1

$$y = 5x^ 2 + 15x − 50$$

$$y=0=> 5x^ 2 + 15x − 50=0$$

$$x^ 2 + 3x − 10=0$$

$$(x+5)(x-2)=0$$

$$x_1=-5, x_2=2$$

(c) (2, 0) and (−5, 0)