1) What is x if the square root of 2x+11 plus 1 is equal to the square root of 5x+1?
1) What is x if 7 minus the square root of 8-x is equal to the square root of 2x+25?
3) What is x if thw cube root of 3x+1 is equal to x+1?
please show complete solutions........
2007-01-17 21:20:58 · 4 answers · asked by blah-blah-black sheep 2 in Science & Mathematics ➔ Mathematics
I'm not too suprised that you need help with this considering that you numbered your question 1, 1, 3.
Also, your question isn't clear enough for an answer. For example would the first one read (square root of 2x) + 11 or square root of (2x + 11)? ....and so forth. Good luck.
2007-01-17 21:28:02 · answer #1 · answered by Some Guy 6 · 0⤊ 0⤋
#1
sqrt(2x+11) + 1 = sqrt (5x+1)
square both sides:
(2x+11) + 2 sqrt(2x+11) + 1 = 5x+1
now get the sqrt alone on one side
2 sqrt(2x+11) = 3x - 11
square both sides again
4 (2x+11) = 9x^2 - 66x + 121
8x + 44 = 9x^2 - 66x + 121
get everything on one side:
0 = 9x^2 - 74x + 77
Now either try to factor that, or use the quadratic equation to solve for x.
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#2
Same process as #1
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#3
cbrt (3x +1) = x + 1
Cube both sides:
3x + 1 = (x+1)^3
Multiply out the right side, then move everything to one side and try to factor.
2007-01-17 21:34:50 · answer #2 · answered by Mathematica 7 · 0⤊ 0⤋
sqr (2x+11) +1 = sqr(5x +1) ==>
4x^2 + 122 +44x = 25x^2 + 10x +1==>
-21x^2 + 34x +121 = 0
The rest is up to you!
2007-01-17 21:34:51 · answer #3 · answered by toxisoft 4 · 0⤊ 0⤋
these are straight forward....set the two equations equal to each other and then solve using rules of exponents, roots, add/sub, etc.
They take work and patience, but they are solvable.
Hint on #3: cube both sides and then solve for x
2007-01-17 21:28:19 · answer #4 · answered by teachbio 5 · 0⤊ 0⤋