Answer:
ab=1/12
Step-by-step explanation:
1/(4ab)+1/(3ab)-1/(2ab)=12
1/(ab)*[1/4+1/3-1/2]=1/12
1/(12ab)=1/12
ab=1
Answer:
Step-by-step explanation:
(2):
First let's organise the data:
33 miles ... x mph ... 4h - downstream
33 miles ... y mph ... 7h - up the stream
x = 33/4 = 8.25 mph
y = 33/7 = 4.71 mph
(3)
P(x) = 
To find the amount of key rings sold when the profit is 5000$ we have to equate P(x) with 5, because in the problem the profit of the key rings is displayed in terms of thousands.

Since the number of keyrings sold has to be positive the only answer is 4 thousand key rings.
Answer:
B - 18
Step-by-step explanation:
Area of a right triangle
1/2 * b * h
1/2 * 9 * 4
1/2 * 36
18
First, distribute what's inside the parenthesis, and change all the subtractions to addition of negatives.
18 + -2 (x^2 + - 5x)
Next distribute the -2
18 + -2x^2 + 10x
Then I like to rearrange stuff to put it in standard form.
-2x^2 + 10x + 18