A. When you add to negative numbers, it is always negative. A positive + a positive is positive. In D, the answer is always 0. 1 + -1 is 0. In C, it varies. The bigger number not including the negative sign is the sign the number has. For example, -6 + 5 = -1. 6 is bigger than 5. You subtract the smaller number from the bigger number and that is the answer. You would then tack on the negative sign because it is -6, and 6 is bigger than 5.
Answer:
y = 4/3x + 1.
Step-by-step explanation:
The equation of the lines passing through (2,1) and (6,7) is:
y - 7 = (7-1)/(6- -2)(x - 6)
y - 7 = 6/8(x - 6)
y = 3/4(x - 6) + 7
y = 3/4x + 5/2.
So the line perpendicular to it has slope -1/3/4 = -4/3:
y - 9 = -4/3(x + 6)
y = -4/3 x - 8 + 9
y = 4/3x + 1.