Well first we got to convert yards and feet into inches.
21 feet=252 inches
11 yards=396 inches
Alright so now that we have the inches needed we must find the cost for both Emily and Andy’s needed wire.
Emily:
We know how much it would cost for 200 inches, which is 8$.
15 inches adds a .60$ increase, which means that 5 inches is equivalent to .20$. By adding that to .60$ we get .80$ or the amount it would cost for 20 inches. We now know how much it would cost for 40 inches, 1.60$.
8+1.60=9.60 or how much it costs for 240 inches.
If it costs .80$ for 20 inches that means it costs .40$ for 10 inches.
9.60+.40=10
To find how much it costs for 2 inches we divide .40 by 5 which is .08.
10+.08=10.08$
Emily will spend 10.08$ for her needed wire.
Andy:
We know how much it would cost for 300 inches, which is 12$.
We also know how much it costs for 20 inches, which is .80$. So we multiply that by 4 to get how much it would cost for 80 inches.
.80*4=3.20
We then add that to the cost of 300 inches.
12+3.20=15.20
We know how much it would cost for 10 inches, which is .40$.
So we add that to the amount it would cost for 380 inches.
15.20+.40=15.60
Finally we know how much it costs for 2 inches, which is .08$. So we multiply that by 3 to find how much it costs for 6 inches.
.08*3=.24
We then add that to how much it would cost for 390 inches.
Sine uses the ratio, so we can plug in the information we know. since there is no current value for the opposite side of angle A, we can just use a variable to replace it.
You can't reduce this any further because there is an unknown variable.