C. "David's equation is correct, because their spending will be multiplied by the number of months and then subtracted from their savings"
they are technically saying "Look we have 12,350 to use. How long (y) will the savings (12,350) last after using 240 each month (x)
so the amount they use *PER* month gets subtracted from the savings because they are using that money to pay with
Hope this helps :)
First off, let's convert the percentages to decimal format, so our 77% turns to 77/100 or 0.77, and our 55% turns to 55/100 or 0.55 and so on
now, the sum of both salines, must add up to the 77% mixture, let's say is "y"
so, 11 + 4 = y, and whatever the concentration level is, must also sum up to the mixture's concentration of 77%
anyway thus
solve for "x"
I cannot see the images, but...
y = | x | + 5
consider the absolute value function. You know that for every value of x, y will be greater than or equal to 5. this means that the y-intercept will also be the bottom of the curve.
Plug a few values in for an idea of what the graph will look like:
f(-1) = 6 (-1,6)
f(1) = 6 (1, 6)
f(-2) = 7 (-2, 7)
f(2) = 7 (2, 7)
The graph will have a minimum value at (0,5), where two lines will converge. The graph will look like a pointy cone with its point at (0,5), with two lines pointing outward and upward from this point. Confirm that the graph passes through the coordinates provided above!
GCF 32 24 40
^ ^ ^
2 16 2 12 2 20
^ ^ ^
2 8 2 6 2 10
^ ^ ^
2 4 2 3 2 5
^
2 2
(2) (2 & 3) (2 & 5)