The answer is AA
good luck
X=5 y=15 (5,15).
This is how you do it:
-4(2x+3y=55): -8x-12y=-220
3(9x+4y=105):27x+12y=315
You add the two new equations together, canceling out the y values, and get the x value. Then, you go back and plug in the x value in the original equation to get the y value.
Answer:
you have to use the Pythagorean theorem. a^2 + b^2= c^2
72^2 + b^2 = 75^2
5184 + b^2 = 5625 (subtract 5184 from both sides)
b^2= 441 (find the square root of each side)
b= 21