Answer:
The answer is 17.
Step-by-step explanation:
what is the average cost of 7 articles if 3 of them cost 30k each and the rest cost 12.5k each
TOTAL NUMBER OF ARTICLE= 7
ARTICLES FOR 30K = 3
ARTICLES FOR 12.5K = 7-3= 4
Average cost of 7 articles
Answer:
x = -122/13 OR 9.3846
Step-by-step explanation:
First, take a look at the second equation. Add 8x to the other side.
-7y= 8x -18
Then, divide by -7 to get a regular "y=" equation.
y= 8/7x -18/7
Move on the the first equation. Let's get "y" by itself. Add 3x to the other side.
y= 3x +15
Considering both equations are equal to Y, set them equal ( except the "y" part )
8/7x - 18/7 = 3x + 15
Multiply all by seven so that there are no fractions.
8x - 18 = 21x + 105
Subtract 8x from both sides.
-17 = 13x + 105
Subtract 105 from both sides.
-122 = 13x
Divide by 13 on both sides.
x = 9.3846
Or if you don't want decimals, just say x = -122/13
Quick Note: I made a mistake. I had looked at the second equation at -18. The answer is incorrect but the method of solving is correct. Also, make sure to plug in the value of x to get Y.
Answer:
C. h=3V/a^2 is the correct answer
Step-by-step explanation:
Given:
V=1/3a^2h
It can be rewritten as
V=1/3 *( a^2) * h
Divide both sides by (1/3)*h
V / (1/3*h) = (1/3)* (a^2) * h / (1/3)*h
V÷1/3*h = a^2
V÷3/1*h=a^2
3V/h=a^2
Multiply both sides by h
3V/h*h=h*a^2
3V=h*a^2
h=3V/a^2
C. h=3V/a^2 is the correct answer
