Math help......8x^2-72=0 solve using discriminant?

Question

How do I solve this problem using only the discriminant?

8x^2-72=0

Answer 1

I'm not sure what your exact question is: In order to determine which of the fractions is bigger, you need to have common denominators (the number on the bottom). Then you compare the number on the top (numerator). For example: a common denominator for 3/4 and 4/5 is /20 because both 4 and 5 go into 20.

3/4 = 15/20 ( got that because I multiplied the 4 by 5 to get 20 and so I had to multiply the 3 by 5 as well- any number multiplied by 1 is itself so 3/4 x 5/5 = 15/20.

4/5 x 4/4 = 16/20

Since 16 is bigger than 15...15/20<16/20 or 3/4<4/5 3/4 is less than 4/5.

Your next answer is incorrect. If you use 36 as your common denominator (because both 12 and 18 go into 36) you get

15/36 and 14/36 so your sentence should read 5/12>7/18 or 5/12 is greater than 7/18.

Alternatively if you're asking how you know what that symbol means or how to read it:

1<2 You read either 1 is less than 2 or 2 is greater than 1. The open side of the greater than/less than symbol always faces the bigger number. When my kids were little I told them to imagine a crocodile and its big open mouth. The croc always eats the bigger number.