The answer to this question:
<span>north and south sides 16ft
east and west sides 8ft
</span>
In this question, the east and west fencing cost is $4/ft but the south and north fencing cost is $2/ft. The cost is cheaper for fencing north and south side which cost half of the east and west side. The perimeter is made by adding the south, north, east and west side.
If x = north and south fencing and y= is east and west side, then you can get this equation
cost= (south+north) * $2 + (east+west)*$4
128=(x+x) * 2 + (y+ y) * 4
128= 4x + 8y
32= x+ 2y
x= 32-2y
The area is count by multiplying the width and length, which was x and y in this question. The formula should be:
area= length * width
area= x * y
area= (32-2y) * y
area= 32y - 2y^2
Then, you need to find the value of y needed for the maximum area.
32y- 2y^2
32 - 2*2y=0
32= 4y
y= 8
If y=8 then
x= 32-2y
x= 32- 16= 16
Let x = first plane's speed.
We have the equation:
2 hours * x km/h + 1.5 hours * (x+60) km/h = 3135 km.
3.5 hours*x km/h + 90 km = 3135km
3.5hours*x km/h = 3045km
x = 870 km/h.
The first plane is traveling at 870 km/h, therefore since it is 60 km/h faster, the second plane is traveling at 930 km/h.
Answer: [C] the length of a soccer field
Answer: he sold 9 pairs of dress shoes.
he sold 4 pairs of athletic shoes.
Step-by-step explanation:
Let x represent the number of pairs of dress shoes that he sells.
Let y represent the number of pairs of athletic shoes that he sells.
The total number of pairs of shoes that he sold in a day is 13. It means that
x + y = 13
The salesman receives a commission of $4 for every pair of dress shoes he sells. He is paid $3 for every pair of athletic shoes he sells. The commission that he got on that day was $48. It means that
4x + 3y = 48- - - - - - - - - - 1
Substituting x = 13 - y into equation 1, it becomes
4(13 - y) + 3y = 48
52 - 4y + 3y = 48
- 4y + 3y = 48 - 52
- y = - 4
y = 4
x = 13 - y = 13 - 4
x = 9
