Question

Can someone please show me how to solve this?
What are the x– and y–intercepts of the graph of y = x2 – 10x + 21?

Answer 1

y = x^2 - 10x + 21

this intercepts y axis at x = 0

substitute x = 0 in to get y coordinate

to find the x intercept we need to solve for x

x^2 - 10x + 21 = (x-7)(x-3)

so when x^2 - 10x + 21 = 0
(x-7)(x-3) = 0

which happens at x = 7 or x = 3

Answer 2

is y 21?

Answer 3

yes

Answer 4

so y intercept is (0,21)

x intercepts are (3,0) and (7,0)