help

(5^2+2x-1)+(-4^2+x+7)

(10+2X-1)+(-8+X+7)

(2X+9)+(X-1)

Answer: 3X+8

Guest:

(5^2+2x-1)+(-4^2+x+7)

(10+2X-1)+(-8+X+7)

(2X+9)+(X-1)

Answer: 3X+8

Hi Guest, thank you for contributing to this question. It is good when people join in.
most of you answer is correct.
However,
In this question the hat ^ is used to indicate power or exponent. So 5^2 means 5 ² which is 5*5 = 25
Often on the forum you will see a multiply sign written as a * This is so that it won't get confused with a x if the question has algebra in it.

So the question really is and since there is a plus in between the brackets i can just leave it out

= 5^2+2x-1+ -4^2+x+7
= 5*5 + 2x - 1 + -4 ² + x + 7

Now, -4^2 is really tricky. Is it -4*-4 = +16? or is it - 4*4=-16 It is always best to use brackets in a situation like this so that the message is clear.
If you do it on your calculator with no brackets you will get -16 Try it and see.
The reason is that the calculator interprets it like this -4^2 = -4 ²= -1 * 4 ²

To be perfectly honest I am not sure how a person is supposed to interpret this. I will ask the other mathematicians whether they have a definite take on this.

For the moment I will interpret it like (-4) ²= -4*-4 = +16 Because I think that was the intent but this does need to be checked.
so

= 5*5 + 2x - 1 + (-4 ) ² + x + 7

= 25 + 2x -1 + +16 + x +7

= 25 -1 + 16 + 7 + 2x + x

= 25 -1 + 16 + 7 + 2x + x

= 47 + 3x

= 3x + 47 (It is always nice to put the x term before the constant)

Melody:

Now, -4^2 is really tricky. Is it -4*-4 = +16? or is it - 4*4=-16 It is always best to use brackets in a situation like this so that the message is clear.
If you do it on your calculator with no brackets you will get -16 Try it and see.
The reason is that the calculator interprets it like this -4^2 = -4²= -1 * 4²

To be perfectly honest I am not sure how a person is supposed to interpret this. I will ask the other mathematicians whether they have a definite take on this.

I would interpret it as:

-4 ² = 0 - 4 ² = 0 - 16 = -16

The expression -x ² is less ambiguous, since it is easy to interpret as -(x ²).

Either way, it's best to use parentheses in cases like these.

Thanks I like Serena.

I'd take it a step further and say that negative number must be enclosed in parentheses when being exponentiated. As you've noted the likelihood for confusion is too great to ever leave it to chance.

Rom:

I'd take it a step further and say that negative number must be enclosed in parentheses when being exponentiated. As you've noted the likelihood for confusion is too great to ever leave it to chance.

Thanks Rom.