Math question help?

Question

(sqrt x+4 )= 3

(sqrt2y+7) +4 = y

(sqrt4x+1) +3 = 0


**********So I have figured out how to complete these problems with help from other Yahoo answer folks. But how do I check the problem to make sure the answer is right *****************

Answer 1

You check the answer by putting the answer where the unknown is in the equation. If the equation remains true, that proves it was the answer.
For example: (sqrt x+4 )= 3
the answer to this is 5
so if we put (sqrt 5+4 )= 3
(sqrt 9)= 3
We know that the square root of 9 is 3.
To double check, you can do 3^2 and see that it is 9.

Answer 2

For example, the answer for the first one is 5=x in sqrt(x+4)=3, insert the 5 in place of the x in the problem{sqrt(5+4)=3}!!!

And in the second one, first transfer the 4 to the other side,{sqrt(2y+7)=y-4} and now square both sides which ends up as{2y+7=y^2-8y+16} then transfer all of the equation to one side and then factor {0=y^2-10y+9}={(y-9)(y-1)} which means y=9 and 1 !!!

In the third one, again transfer {sqrt(4x+1)=-3} then square both sides {4x+1=9}which means x=2 !!!

Did that help or confuse u more? ;)

Answer 3

Just plug your answer back into the equation for x. If it comes back as a true statement, then it was correct. Otherwise it isn't.

For example, I suspect the first answer is 5...

sqrt((5) + 4) =? 3
sqrt(9) =? 3
3 =? 3 <-- check, so the answer is x = 5.

Now try it the other way... let's say you thought the answer was 12.

sqrt((12) + 4) =? 3
sqrt(16) =? 3
4 =? 3 <-- not correct, so the answer is *not* 12.

Answer 4

square root of x + 4 = 3
square root of x = 7
x = 49

? did I misread the question?

Answer 5

check the work by butting in the answers or working backwards