Solve sqrt(4x - 3) + 10 / sqrt(4x - 3) = 7
First note that the expression 4x - 3 is under the square root sign.
Since this value must be positive: 4x - 3 >= 0 ---> 4x >= 3 ---> x >= 4/3
To remove the denominator from the problem multiply each side by sqrt(4x - 3):
sqrt(4x - 3) [ sqrt(4x - 3) + 10 / sqrt(4x - 3) ] = sqrt(4x - 3) [ 7 ]
---> sqrt(4x - 3) · sqrt(4x - 3) + sqrt(4x - 3) · 10 sqrt(4x - 3) = 7· sqrt(4x - 3)
---> (4x - 3) + 10 = 7 · sqrt(4x - 3)
---> 4x + 7 = 7·sqrt(4x - 3)
Square both sides: [ 4x + 7 ]2 = [ 7·sqrt(4x - 3) ]2
4x2 + 56x + 49 = 49(4x - 3)
---> 4x2 + 56x + 49 = 196x - 147
Subtract 196x from both sides, add 147 to both sides:
---> 4x2 - 140x + 196 = 0
Divide both sides by 4:
---> x2 - 35x + 49 = 0
Factor: (4x - 7)(x - 7) = 0
So, either 4x - 7 = 0 ---> x = 7/4 or x - 7 = 0 ---> x = 7
Since both answers are > 4/3, these are possible answer.
I'll leave the check for you ...