Answer:
d
Step-by-step explanation:
base² + Altitude² = Hypotenuse²
x² + 9² = 13²
x² + 81 = 169
x² = 169 - 81
x² = 88
x = 

<span>The correct answer is 1.
Explanation:
The way this is written, everything after the words "divided by" would be calculated first; it is written as though this is a grouping, such as 20/(2*(5+5)). We would evaluate the innermost parentheses first; 5+5=10. Then this gives us 2*10=20 in our parentheses. 20/20 = 1.</span>
I'm assuming you're talking about the indefinite integral

and that your question is whether the substitution

would work. Well, let's check it out:



which essentially brings us to back to where we started. (The substitution only served to remove the scale factor in the exponent.)
What if we tried

next? Then

, giving

Next you may be tempted to try to integrate this by parts, but that will get you nowhere.
So how to deal with this integral? The answer lies in what's called the "error function" defined as

By the fundamental theorem of calculus, taking the derivative of both sides yields

and so the antiderivative would be

The takeaway here is that a new function (i.e. not some combination of simpler functions like regular exponential, logarithmic, periodic, or polynomial functions) is needed to capture the antiderivative.