Respuesta :

5+x²=2x²+13

what we are trying to do here is get all of our variables on one side, and get all of our numbers on the other side of the equal sign.

so our first step will be to move the 5 first, this 5 is positive, so we will subtract it from both sides.

5+x²=2x²+13

-5             -5

x²=2x²+8

our next step is to move the 2x² so that all of our variables are together on one side of the equal sign:

because it is positive, we will subtract it from the other side in order to move it.

x²=2x²+8

-2x² -2x²

we would get -x² on the left side of the = because there will always be an invisible 1 in front of a variable if it has no other number.

so: -x²=8

what we do now is get rid of the negative sign on the left hand side by dividing:

-x²=8

/-1    /-1

our answer would be:    x²=-8


for the second one:

5+x³=2x³+13

x³-2x³=8

-x³=8

x³=-8