Question 194802: I have these 3 problems left and i cannot figure them out someone please help asap id really appreciate it.
Solve the equation for x.
1.
2.
3.
Found 2 solutions by stanbon, RAY100:
Answer by stanbon(75887)   (Show Source):
Answer by RAY100(1637) (Show Source):
You can put this solution on YOUR website! 1) sqrt (x) -5 =7
,,,,sqrt(x) =12
squaring
x = 144
checking
sqrt(144) -5 =12-5 =7,,,,ok
or if the problem is
sqrt (x-5) =7
squaring
x-5 =49
x=54
checking
sqrt(54-5) = sqrt(49) =7,,,ok
.
2) sqrt (3x) / sqrt(2x+3) =2
squaring
(3x) / (2x+3) = 4
cross multiply
3x = 4 (2x+3) = 8x +12
-5x = 12
x=(-12/5) ,,,,,,ANSWER
checking
sqrt(3(-12/5) / sqrt( 2(-12/5) +3) = 2
sqrt -36/5 / sqrt (-24 /5 +3) =2
sqrt -36/5 / sqrt ( -24/5 +15/5) =2
sqrt -36 /5 / sqrt -9/5 =2
sqrt ( -36 /-9) = sqrt (4) =2
2=2,,,,,,ok
.
3) sqrt(x+5) = x+3
squaring
(x+5) = (x+3)^2 = (x+3)(x+3) =x^2 +6x +9
0 = x^2 +5x +4
0 = ( x+1) (x+4)
x = -1, -4
checking
x=-1 ,,,, sqrt(-1+5) = (-1+3),,,,sqrt 4 = 2,,,,,,,ok
for x=-4,,,,,,sqrt ( -4+5) = (-4+3),,,sqrt (1) = -1,,, ok,,,realizing sqrt1= +/- 1
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