Question

Determine whether or not each of the following points is a solution of the inequality y 2x2 + 3x -5.

1. B (1,8)
2.C (-5,10)
3. D (3,6)
4. E (-3,4)
5. F (2,9)​

Answer 1

E(-3,4) and F(2,9)

Explanation:

If we plug in for x to see what we get for y:

(1,8):

y = 2(1)^2+ 3(1) - 5

y = 2 + 3 - 5

y = 0

This is wrong.

(-5,10):

y = 2(-5)^2 + 3(-5) -5

y = 50 - 15 - 5

y = 30

This is wrong.

(3,6):

y = 2(3)^2 + 3(3) - 5

y = 18 + 9 - 5

y = 22

This is wrong.

(-3, 4):

y = 2(-3)^2 + 3(-3) - 5

y = 18 - 9 - 5

y = 3

This is correct!

Lets check the last one...:

(2,9):

y = 2(2)^2 + 3(2) - 5

y = 8 + 6 - 5

y = 9

This is also correct!

So your right answers are:

E and F!

Hope this helps! :D