1) You must do division first. So divide 5/12 and get .41666666...
2) Then you add 15+5 and get 20.
3) Finally you subtract 20 and .41666666... and you get 19.5833333...
4) you can simplify 19.583333... to 19.584 if you need to.
Three would fit cause 3 times 12 is 36 and 4 times 12 is 48 which would be too big
Direct variation is y=kx where k is a constant
the fiest way to see if it is direct or not, is if x increases, then y increases as well,
then we see if y=kx is valid, basically if we have a constant of variation
the first one x increase and y increase
see if same constant
y=kx
-4.5=-3k
1.5=k
so
see next one
-1 and 3
-3=-1(k)
-3=-1(1.5)
-3=-1.5
false
not it
2nd is increase and y decrease, so not direct variation
3rd is x is same but y increase so nope
4th is x increase and y increase, now test the constant
-7.5=-3k
2.5=k
-1 and -2.5
-2.5=-1k
-2.5=-1(2.5)
-2.5=-2.5
true
answer is last option
Answer:
Below in bold.
Step-by-step explanation:
y = 2x²-4
First find x in terms of y:
2x² = y - 4
x² = (y - 4)/2
x = √ [(y - 4)/2]
Now replace x by the inverse f-1(x) and y by x:
f-1(x) = √ [(x - 4)/2] (Note: it's the positive square root only)
5.59 miles = 9 kilometers