Find the sum of the solutions of the equation: x − 3 + 2 x − 2 = 2 .
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Too many squaring steps! But an awesome approach! :D
Log in to reply
Yes, double yours but only twice. But no substitution.
Log in to reply
Sizes don't matter, variation in methods of solving does. :)
We have, x − 3 + 2 x − 2 = 2
⟹ x − 3 + 2 × x − 1 = 2
Let u = x − 1 ⟹ u 2 = x − 1 ⟹ u 2 − 2 = x − 3
Hence, our equation becomes:
u 2 − 2 = 2 − 2 u
Squaring both sides, we have:
u 2 − 2 = 4 − 4 2 u + 2 u 2 ⟹ u 2 − 4 2 u + 6 = 0 ⟹ u = 2 , 3 2
Since u = x − 1 , we have x = 3 and x = 1 9 . But substituting these values in the primitive equation, we find that only x = 3 is a solution but x = 1 9 isn't. So we find that the only legitimate solution to the equation is 3 .
Problem Loading...
Note Loading...
Set Loading...
x − 3 + 2 x − 2 x − 3 + 2 ( x − 3 ) ( 2 x − 2 ) + 2 x − 2 3 x − 9 9 ( x − 3 ) 2 ( x − 3 ) ( 9 x − 2 7 − 8 x + 8 ) ( x − 3 ) ( x − 1 9 ) ⟹ x = 2 Squaring both sides = 4 Rearranging = − 2 ( x − 3 ) ( 2 x − 2 ) Squaring both sides = 4 ( x − 3 ) ( 2 x − 2 ) Rearranging = 0 = 0 = { 3 1 9 ⟹ 3 − 3 + 2 ( 3 ) − 2 = 2 ⟹ 1 9 − 3 + 2 ( 1 9 ) − 2 = 1 0 = 2 Accepted Rejected
The sum of solutions is 3 .