Answer:
8: 50 hours
9: 6 inches
10: 43 cm
Step-by-step explanation:
I couldn't see the entirety of 7 because some of the page was folded, so I didn't answer it.
8: Make them equations of y=12x+450 and y=21x. Since both equal y, set them equal to each other so 21x=12x+450. Subtract 12x from both sides to get 9x=450. Divide by 9 on both sides to get 50.
9: The length equals 3w-6 and the width is just w. The perimeter would equal 2w+2(3w-6) which when factored is 2w+6w-12. Simplify to 8w-12. If P=8w-12 and we know P=36, then set the two equations equal to each other so that 8w-12=36. Add 12 to both sides to get 8w=48. Then divide both sides by 8 to get a final answer of w=6.
10. P=x+5x+8+4x-7. Simplify that to P=10x+1. We know that P=71, so set the two equations equal to each other to get 71=10x+1. Subtract 1 from both sides to get 70=10x. Divide both sides by 10 and x=7. Now substitute x in each side of the triangle and we get 7, (4*7-7), and (5*7+8). Solve all of those to get sides of 7, 21, and 43. The question asks what is the length of the longest side, so the answer would be 43.
