Answer:
infinitely many solutions
Step-by-step explanation:
We want to find solution to the system:
-4y=-20x+40
y+10=5x
We make y the subject in the second equation to get;
y=5x-10
We substitute y=5x-10 into the top equation to get:

We expand to obtain;

This implies that:

Therefore the system has infinitely many solutions.
Answer: speed of the car is 88 miles per hour
the speed of the motorcycle is 78 miles per hour
Step-by-step explanation:
Number of miles travelled by car = 312
Number of miles travelled by motorcycle = 272
Let x = speed of the car
Let y = speed of the motorcycle
If the car's speed is 10mph more than the motorcycle's, it means
x = y + 10 - - -- - - 1
Time taken for car to travel 312 miles is distance /speed = 312/x
Time taken for motorcycle to travel 272 miles is distance /speed = 272/y
The car travels 312 miles in the same time that a motorcycle traveled 272.
This means
312/x = 272/y
312y = 272x
y = 272x/312
Substituting y = 272x/312 into equation 1, it becomes
x = 272x/312 + 10
312x = 272x + 3120
312x-272x = 3120
40x = 3120
x = 3120/40 = 78 miles per hour
x = y + 10 = y + 78
x = 88 miles per hour
Answer:
A = $32,652.44
Step-by-step explanation:
Given: Principal (P) = 30,760.08, Annual Rate (R) = 12%, Time (t in years) = 0.5
To find: How much David needs to invest monthly
Formula: 
Solution: To find, simply add principal + interest
First, convert R as a percent to r as a decimal
r = R/100
r = 12/100
r = 0.12 rate per year,
Then solve the equation for A
A = P(1 + r/n)nt
A = 30,760.08(1 + 0.12/12)(12)(0.5)
A = 30,760.08(1 + 0.01)(6)
A = $32,652.44
Therefore;
The total amount David will obtain with 30,760.08 for 6 months, 12%is $32,652.44.
Answer:
its B because
Step-by-step explanation:
Simplifying
41n(7x) = 8
Remove parenthesis around (7x)
41n * 7x = 8
Reorder the terms for easier multiplication:
41 * 7n * x = 8
Multiply 41 * 7
287n * x = 8
Multiply n * x
287nx = 8
Solving
287nx = 8
Solving for variable 'n'.
Move all terms containing n to the left, all other terms to the right.
Divide each side by '287x'.
n = 0.02787456446x-1
Simplifying
n = 0.02787456446x-1
Answer:

Step-by-step explanation:
Let c represents child bikes and a represents adult bikes.
Given : Each child bike requires 4 hours to build and 4 hours to test. Each adult bike requires 6 hours to build and 4 hours to test.
With the number of workers, the company is able to have up to 120 hours of building time and 100 hours of testing time for a week.
Then, the required system of inequality :-

If company make 10 child bikes and 12 adult bikes in the week.
Then Put c=10 and a=12 bikes in (1) and (2).
⇒Bike order meets the restrictions
⇒Bike order meets the restrictions
Hence, the system of inequality best explains whether the company can build 10 child bikes and 12 adult bikes in the week.
