What are the x-intercept(s) of the graph of y + 20 = x2 − x?

(−4, 0) and (−5, 0)

(−4, 0) and (5, 0)

(4, 0) and (−5, 0)

(4, 0) and (5, 0)

Question

What are the x-intercept(s) of the graph of y + 20 = x2 − x?

 (−4, 0) and (−5, 0)

 (−4, 0) and (5, 0)

 (4, 0) and (−5, 0)

 (4, 0) and (5, 0)

phi · Answer

first, notice you can rewrite
 $$y+20= x^2-x $$
as
 $$y= x^2-x-20 $$
the x-intercepts happen when y is zero.  So the question is asking "what x's make this 0 ?"
 $$x^2-x-20 =0 $$
can you factor this?  (that is how you find what x's make it zero)

phi · Answer

or, you can try the different possible solutions given, and see which pair give 0 when you replace x with a number in the equation