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2007-05-07 10:12:45 · 12 answers · asked by Anonymous in Science & Mathematics Mathematics

12 answers

√x+7=5

use inverse operations...

√x+7=5 ... subtract 7 from both sides
√x = -2 ... square both sides
x = 4

*** wow! you are right, this can't be the answer, but I followed all inverse operations rules, wonder why it doesn't work... it would be 4i not 4. hmmmm how come inverse doesn't work to solve this? can anyone help me?

or if the problem is √(x+7) = 5

√(x+7) = 5 ..... square both sides
x + 7 = 25 ..... subtract 7 from both sides
x = 18

2007-05-07 10:19:43 · answer #1 · answered by JirafaBo 2 · 1 0

If you are studying Complex Numbers...

Then, your answer is 4i where i^2 = -1.

If you aren't, then it's probably supposed to be sqrt(x+7)=5, which makes x=18. (square both sides to get x+7=25 => x=25-7=18.

For those answering 4...

put 4 back into the equation to check the answer, you get sqrt(4)+7=5 or 2+7=5, but that is an inequality. There is no "real" solution... No solution in the Real Numbers. x's value is in the complex number system.

2007-05-07 10:34:46 · answer #2 · answered by Jason K 2 · 0 0

If it is sqrt(x) +7=5 No solution as sqrt(x) >=0
so if
sqrt(x+7)=5 x must be >= -7
squaring both sides
x+7= 25 so x=18

2007-05-07 10:22:15 · answer #3 · answered by santmann2002 7 · 0 0

√x+7=5 (-7 both sides)
√x=-2 (square both sides)
x = 4

2007-05-07 10:20:17 · answer #4 · answered by Anonymous · 0 0

First, subtract 7 from both sides. That gives you x^(1/2) = -2

Now, square both sides:

x^(1/2)(2) = 4 or x=4

2007-05-07 10:23:11 · answer #5 · answered by Anonymous · 0 0

To find x you must subtract 7 from both sides. Therefore x=-2

The square root of -2 is -1.41421356

Therefore this is the answer

2007-05-07 10:32:13 · answer #6 · answered by wankerfromacrosstheroad 2 · 0 0

sqrt( x ) + 7 = 5
given expression

sqrt( x ) = 5-7

sqrt (x ) = -2

[sqrt ( x )]^2 = (-2)^2
Taking square on both sides. In this way sqrt and power 2 will cancel each other on left side.

x = (-2)(-2)

x = 4
answer

2007-05-07 10:24:03 · answer #7 · answered by nido 2 · 0 0

The person who says x=4 is right, ignore the others.

2007-05-07 10:21:01 · answer #8 · answered by soelo 5 · 0 0

Therefore, sqrt x = 2, therefore x=4.

2007-05-07 10:35:50 · answer #9 · answered by Paul R 2 · 0 0

the sqaure root of x= -2
Invalid Function

2007-05-07 10:23:21 · answer #10 · answered by Anonymous · 0 0

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