What's the issue? You gave the possible answers but that's about it.
It's a linear function. The graph is a straight line, therefore we need only two points.
Select any value of x and calculate the value of y:
y = -3x + 4
for x = 0 → y = -3(0) + 4 = 4 → (0, 4)
for x = 2 → y = -3(2) + 4 = -2 → (2, -2)
Let

be the number of boxes the team brings with them. Their weight combined with the boxes can't exceed the capacity of 1400. Assuming the elevator runs fine at that exact weight, you want to find the number of boxes, each of which contributes 40 pounds. This is given by the equation

Solving for

, you have



So the team can bring *at most* 5 boxes at a time.
6 in the hundreds place = 600
6 in the tens place =60
Answer: Complementary angles. x = 60
How I got it.
x - 30 + x = 90
then solve for x
Hope this helps!