1. Which equation has this graph?

a)y = x2 + 5x + 8
b)y = x2 - 5x + 8
c)y = -x2 - 5x - 8
d)y = -x2 + 5x - 8

Question

1. Which equation has this graph?

      a)y = x2 + 5x + 8
      b)y = x2 - 5x + 8
      c)y = -x2 - 5x - 8
      d)y = -x2 + 5x - 8

anonymous · Answer

attachment

jim_thompson5910 · Answer

It opens upwards, so you know it has a positive leading coefficient. So you can eliminate choices C and D

jim_thompson5910 · Answer

The graph goes through (4,4), so let's test choice A


y = x^2 + 5x + 8

4 = (4)^2 + 5(4) + 8

4 = 16 + 20 + 8

4 = 44 ... which is false, so choice A is NOT the answer

So it has to be choice B, let's check (4,4) here as well

y = x^2 - 5x + 8

4 = (4)^2 - 5(4) + 8

4 = 16 - 20 + 8

4 = 4 ... which is true, so this graph goes through (4,4)

So this partially confirms that the answer is choice B

anonymous · Answer

thank you so much for going over that!

jim_thompson5910 · Answer

you're welcome