Note: y = x2 + 3x - 10 should be y = x^2 + 3x - 10, where " ^ " indicates exponentiation.
To find the y-int.: Let x = 0 and find y. That intercept is (0, -10).
To find the x-int.: Set y = x^2 + 3x - 10 = to 0, and solve for x. You could, for example, use the quadratic formula, completing the square, graphing, factoring, etc. x^2 + 3x - 10 = 0 can be factored easily:
(x+5)(x-2)=0, so that x = -5 and x=2. The x-int. are (-5,0) and (2,0).
The x-coord. of the vertex can be found by using the formula x = -b/(2a).
Once you have that, subst. that result into the given formula and calculate y.
The line of symm. has precisely the same form: x = -b/(2a), where
b=3 and a = 1. Here we don't need or care about c= -10.
