Question

Find the smaller solution for
3/5x^2−7=21 .

Answer 1

Is this the question?:
3/(5x^2) -7 = 21

Answer 2

no , 3over5xto the second power minus 7 equals 21

Answer 3

so like:
3/(5x^2 - 7) = 21 ?

Answer 4

yeah i guess

Answer 5

are you sure? It is important.

Answer 6

yeah its like that

Answer 7

So first I would multiply both sides by (5x^2 - 7):
3 = 21(5x^2 - 7)

then expand the left side:
3 = 105x^2 - 147

then add 147 to each side:
150 = 105x^2

then divide both sides by 105:
150/105 = x^2

Is that as far as they want you to go with it? Or did I still misunderstand the question?

Answer 8

EDIT: expand the right side*

Answer 9

yeah , its not like that :/

Answer 10

is it like \[3/5 x^2 - 7 = 21\] ?

Answer 11

yes !!!!!! :) lol

Answer 12

ok so add 7 to each side:
(3/5)x^2 = 21 - 7
(3/5)x^2 = 14

divide both sides by (3/5):
x^2 = 14/(3/5)
x^2 = 14 * (5/3)

x^2 = 70/3

Hows that?

Answer 13

what 70/3 what does that mean ?

Answer 14

/ means division

when you divide 70 by 3 you get 23.33....

Answer 15

Then you find the squar root ?

Answer 16

are you solving for x?

if you are then you take the square root of both sides:
x =about 4.83

(it can also be -4.83 but I don't know if you're expected to know that)

Answer 17

yes thats the answer thank you

Answer 18

no problem. do you understand how i found it?

Answer 19

yea i got it

Answer 20

great