Since this is a right triangle, you can use the pythagorean theorem,
, to find XY. Since we know that 15 and 17 are our legs and that XY is the hypotenuse, we can solve it as such:

In short, XY is √514, or 22.67 rounded to the hundreths, units long.
The answer to 4 1/5 divided by 2 4/5 is 3/2
An infinite number of solutions means a coincident line...it is the same line
3y = 2x - 9...divide by 3
y = 2/3x - 3...hmm...same line as answer choice b....they are coincident lines and have infinite solutions
To estimate 2641 x 9 is that you round each number. so it would be 2641 to 2640 and the 9 would round to 10. 2640 x 10