Question

What is the y value of the vertex?
y=x^2-10x+24

Answer 1

hack way
find x value then plug back
to find the x value of the vertex in form
y=ax^2+bx+c
the x value is -b/(2a)

so

y=1x^2-10x+24
x value is -10/(2*1)=-10/2=5

sub back

y=5^2-10(5)+24
y=25-50+24
y=25+24
y=49
y value is 49

Answer 2

x from -6 to 25, y from -50 to 10, x^2 -10x -24 

vertex=(5,-49)
x intercept=-2 & 12
y intercept=-24