Question

underroot 15 -2x=x

Answer 1

square both sides\[\LARGE{{(\sqrt{15-2x})^2=x^2}}\]

Answer 2

oh square both sides?

Answer 3

so now it becomes\[\LARGE{15-2x=x^2}\]

Answer 4

then?

Answer 5

now\[\LARGE{0=x^2+2x-15}\]

Answer 6

now solve this equation

Answer 7

can u @annie1111 ??

Answer 8

no I am lost

Answer 9

ok first factor L.H.S

Answer 10

\[\LARGE{0=x^2+5x-3x-15}\]

Answer 11

\[\LARGE{0=x(x+5)-3(x+5)}\]

Answer 12

\[\LARGE{0=(x-3)(x+5)}\]

Answer 13

\[x = \frac{-b \pm {\sqrt{b^{2}-4ac}}}{2a}\]

Answer 14

so now roots come as
x=3 & 5

Answer 15

hence it is ur answer @annie1111 :)

Answer 16

gt it @annie1111 ???????

Answer 17

oh but in the book the anser is 3 only?

Answer 18

maybe they ignore negative values

Answer 19

ok

Answer 20

but there is no negative valu ehere 5 and 3 both are positive

Answer 21

and just check ur answer by substituting

Answer 22

I did it only says 3 as the answer

Answer 23

so 3 is only the answer;)

Answer 24

did u understnd?

Answer 25

yeah but what happened to 5?

Answer 26

sorry x=3&-5

Answer 27

(x-3)(x+5) = 0
x-3 = 0
X= 3 (one answer)

x+5 = 0
x = -5 ( second answer)

now substitute both answers in the equation 15 -2x = x^2
15 - 2(3) = 9