Question

√(x+4)+√(2x+6)=7

Answer 1

rsmith almost gets the question right.

(a+b)^2 = a^2 + 2ab + b^2,

Answer 2

this is how I'd approach it:
\[ \sqrt{x+4} = 7 - \sqrt{2x+6} \]
\[ x+ 4 = 49 + (2x+6)-14 \sqrt{2x+6} \]
\[ x + 4 -49 -2x-6=-14\sqrt{2x+6} \]
\[ -x -51 = -14\sqrt{2x+6} \]
\[ x+51 = 14\sqrt{2x+6} \]

I am sure you can continue and solve this equation now.

Answer 3

@ rsmith, you can validate whether your answer is correct by plugging x=13 into the equation

sqrt(13+4) + sqrt(2*13+6) =7
sqrt(17) + sqrt(32) = 7 ?

Answer 4

dont u got to do the one and the ( and here first then u have to to keep bringing it down

Answer 5

till u get ur answer or change keep oppisite

Answer 6

@oojih where are you going with your solution?

Answer 7

i think am right yay

Answer 8

Just square both sides:

3x+10+ 2 sqrt(......=49) etc etc.

Answer 9

@ rsmith,

you need to square the equation one more time to get rid of the square toot, then it boils down to a quadratic equation whic looks prett nasty from the number.

Answer 10

u have to add

Answer 11

u confuse me

Answer 12

yes x^2 + 102x + 2601 = 196(2x+6) does look nasty

Answer 13

am correct

Answer 14

\[ x+ 51 = 14 \sqrt{2x+6} \]
\[ (x+51)^2 = 14^2 (2x+6) \]

yes..mr rajah can solve this fun quadratic equation

Answer 15

check out http://www.oojih.com/displaypage/algebra/ for more algebra study guide and practice test.

Answer 16

x^2 - 290x +1425 = 0

Answer 17

you are right oojih. :) roots are 285 and 5. 285 is not sensible so the root being 5 works

Answer 18

sqrt(5+4) + sqrt(2*5+6) =7
sqrt(9) + sqrt(16) = 3 + 4 = 7...

yaayy, good job rsmith

Answer 19

I command you for solving the quadratic equation..:)
This is a good math question, but the number should be made simpler so that students get the concept instead of being bogged down by this ugly number.

Answer 20

true that