Patrick worked 160.5 hours because you have to subtract 1000 from 7420 then divide that by 40 for your answer. Also, Patrick has a sweet job.
A carpenter's square is a ruler which looks like a right triangle. Being such, it has a long side and a short side. Assuming that the radius of each wheel is the size of the short side, we can use this to measure the mid point of the wheel. The mid point of the wheel is the optimal point where you can bore a hole.
Given a table, with an input (x) and output (y) , you could actually use the slope formula to get the rate of change because slope is the same thing as rate of change. If you recall, the slope formula is (y2-y1)÷(x2-x1)
Just pick two points from the chart and plug them in and that is your rate of change
"31-inch piece of steel is cut into three pieces"
Call the pieces a,b,c
a + b + c = 31
"second piece is twice as long as the first piece"
b = 2a
"third piece is one inch more than seven times the length of the first piece"
c = 1 + 7a
Ok, we have our equations, let's substitute the second and third into the first.
a + 2a + 1 + 7a = 31
10a + 1 = 31
10a = 30
a = 30/10 = 3
b = 2a = 6
c = 1 + 7a = 22
Check: 3 + 6 + 22 = 31, good
Answer: 3 inches, 6 inches, 22 inches
Total cost = student cost + adult cost
t = 25s + 3(s+3)
t=28s+9
