Question

Solve by isolating the x^2 term and taking the square roots ( + and - ).

1. x^2 = 25
2. x^2 - 16 = 0
3. -2x^2 + 40 = 0

Answer 1

recall
\[\sqrt{x^2}=\left| x \right|\]

Answer 2

oh so you just find the square root of 25

Answer 3

?

Answer 4

how about x^2 - 16 = 0, do you add 16 to both sides?

Answer 5

yes, square root both sides of the =, and remember the abs value

Answer 6

abs value of x = 5, so x can be + or - 5

Answer 7

oh so its x = |5|

Answer 8

same for the second, isolate the x^2, take the square root of everything

Answer 9

square root of 16 is 4

Answer 10

yes, and the square root of x^2 = absolute value of x

because x^2 will be the same for the + or - value of x

Answer 11

ahh i see alright thanks!, now how abbout the 3rd one? what step do i do first

Answer 12

\[\sqrt{x^2}=\sqrt{16}\]
\[\left| x \right|=4\]
x=+ 4 or x=-4

Answer 13

gotcha

Answer 14

try the last one

Answer 15

is it x^2 - 20 = 0

Answer 16

ok, so you divided everything by -2

Answer 17

yep

Answer 18

k, same as #2 prob now

Answer 19

ohh okay i see now thanks!

Answer 20

you can do whatever operation you want, as long as it is to both sides of the equation

Answer 21

alright gotcha tyvm

Answer 22

i just think move the 40 over by subtracting 40
isolate x^2 by dividing everything by -2
square root everything

Answer 23

welcome