please help me with math homework?

Question

Solve for x: 5x(squared) - 10 = x (squared) + 90

thanks everyone ,so is it 5 or -5 or x=5,x=-5?

Answer 1

5x^2 -10 = x^2 + 90

Add 10 to each side:

5x^2 = x^2 + 100

Subtract x^2 from each side:

4x^2 = 100

Divide by 4:

x^2 = 25

square root each side

x = 5

Answer 2

x = -5 or 5

bring the right x^2 over to the left,
and bring the -10 to the right
5x^2-x^2=90+10
4x^2=100
x^2=100/4
x^2=25
x = -5 or 5

Note: (-5)^2 = 25
btw ^ means to the power of.. 5^2 means 5(squared)

Answer 3

5x^2-10=x^2+90, move them all to one side...
4x^2-100=0, take out 4
x^2-25=0, this is a great state for the problem because it fits (a-b)(a+b)=a^2-b^2
so this can be separated into (x-5)(x+5)=0
isolating each quantity, we get x=5,-5

***Others are getting answers of just 5, which is not complete; a value -5 also works***

Answer 4

5x^2 - 10 = x^2 + 90
5x^2 = x^2 + 100
4x^2 = 100
x^2 = 25
x = 5