Question

Find the value(s) of x that make the following equation true: √-4x+5 =x

Answer 1

square both sides

Answer 2

and then you solve the quadratic

Answer 3

-4x+5 = x^2

Answer 4

0 = x^2+4x-5

Answer 5

yes

Answer 6

then.....

Answer 7

then factorize the quadratic.

Answer 8

Ya, I'm having trouble with that part.

Answer 9

we need two numbers such that
(a) their product = -5
(b) their sum = +4

Answer 10

can you think of any?

Answer 11

-1 and 5

Answer 12

5 and -1

Answer 13

good
no,
\[0=(x-1)(x+5)\]

Answer 14

so,
\[x=1\qquad{\rm AND}\qquad x=-5
\]

Answer 15

Ya, i was getting to that. Thanks

Answer 16

lets see if they both satisfy the given problem or not

Answer 17

plug in x=1 and see if it satisfies the given equation before you squared it!

Answer 18

yes

Answer 19

now, what about
x= -5
??

Answer 20

no

Answer 21

good
coz,
\[\sqrt{-4(-5)+5}=\sqrt{25}=5\ne-5\]

Answer 22

so, there is only one value for "x" that can satisfy the given equation and that is,
x=1

Answer 23

yes. Thanks

Answer 24

good job people.