Which ordered pairs in the form (x, y) are solutions to the equation 3x – 4y = 21? choose all answers that are correct.
a. (−3, 3)
b. (−1, −6)
c. (7, 0)
d. (11, 3)

A. (−3, 3)
3x – 4y = 21
3(-3) - 4(3) = 21
-21 = 21 >>>>> not equal

B. (−1, −6)
3(-1) - 4(-6) = 21
21 = 21 >>>>>>>>>>Equal

C. (7, 0)
3(7) - 4(0) = 21
21 = 21>>>>>>>>>>equal

D. (11, 3)
3(11) - 4(3) = 21
21 = 21 >>>>>>>>>equal

8 -

Step-by-step explanation:

For this problem you have to use the 45-45-90 triangle theorem and 30-60-90 theorem.

For 45-45-90, the isosceles sides = 4, so the hypotenuse of the 30-60-90 triangle is 4 times 2, which is 8. If x is 8, then since y is the side across from the 60 angle, y is . Since this really can't be simplified after y is subtracted from x, the final answer is just 8 - .