Answer:
-1
Step-by-step explanation:
2x² - 5x + 7 is subtracted <em>from </em>x² + 2x - 11, so
(x² + 2x - 11) - (2x² - 5x + 7)
x² + 2x - 11 - 2x² + 5x -7 (Distribute the negative)
-x² + 7x - 18 (Combine like terms)
The leading coefficient is the coefficient of the first term, so it is -1.
Your reasoning and your answer were both correct. Discuss with the teacher. ("Discuss". DON'T fight.)
Actually, the answer is not A, if you're saying A is the first choice above. That's incorrect. You will need to use the Geometric mean for right triangles here to figure out what the value of a is. We will use this form:

. We have a value for YZ of 3; side a is XZ. That means in order to solve this we need WZ, which we can find using pythagorean's theorem. 3^2 + 4^2 = c^2 and 9 + 16 = c^2 and c = 5. Now we fill in accordingly:

. Cross-multiply to get 3XZ=25 and side XZ is

. XZ is 25/3 and YZ is 3, so 25/3 - 3 = XY. That means that XY (side a) = 16/3 or 5 1/3, choice B, or the second one down.
3.16 is the correct answer
Answer: 3 3/4
Step-by-step explanation: brainliest plsss