1. Take an arbitrary point that lies on the first line y=3x+10. Let x=0, then y=10 and point has coordinates (0,10).
2. Use formula 
to find the distance from point 
to the line Ax+By+C=0.
The second line has equation y=3x-20, that is 3x-y-20=0. By the previous formula the distance from the point (0,10) to the line 3x-y-20=0 is:
.
3. Since lines y=3x+10 and y=3x-20 are parallel, then the distance between these lines are the same as the distance from an arbitrary point from the first line to the second line.
Answer: 
.
1. -3
2. 28
3. 88
4. -5
5. -28
Let x = total distance he covered
3x/4 by bus
1/2 . x/4 = x/8 by jogging
the remaining distance = x/8 by walking
thus x/8 = 800ft
x = 8 . 800 = 6400ft
Dear SailorMars, since I don't have a phone I will show my work on this chat. For 2. we can do 1x1x28=28 cm³ and 2x2x7=28cm³ which will have a square base, which is 2 possible molds. For 3. we can do 10x1x36=360in³, 10x2x18=360in³, 10x3x12=360in³, 10x4x9=360in³, and 10x6x6=360in³ which will have a dimension of 10 in, which is 5 possible molds.
For 4. multiply 12x8x4=384in³ and multiply 20x15x9=to get 2700in³. With the two measurements, subtract 2700-384=2316in³ of space in the box.
For 5. multiply the equations 5x2x1, 5x2x2, 5x2x3, 5x2x4, and 5x2x5 to get the volumes in order 10ft³, 20ft³, 30ft³, 40ft³, and 50ft³.
For 6. multiply the equations 3x6, 3x7, 3x8, 3x9, 3x10, 3x11, and 3x12 to get the inches in order 18 in, 21 in, 24 in, 27 in, 30 in, 33 in, 36 in.
For 1. multiply 6x8x10 to get 480 in³; the answer is C
For 2. multiply 12x8=96 and divide 576/96 to get 6 in; the answer is A
For 3. 7:50+ :28= 8:18 PM then 8:18+2: =10:18 PM; the answer is D
For 4. it's a square pyramid because a square pyramid has squares and pyramids; the answer is D
For 5. multiply 24x12x14=4032 in³; the answer is D
For 6. multiply 2x3x6 to get 36m³; the answer is C
Supplier A: $188.6
Supplier B: $221.6
I hope I helped but I honestly have no idea if I did. Anyway sorry if I didn't. Good luck.
