Of usually means multiply
1/3 x 3/7
=3/21
Answer:
First table
Step-by-step explanation:
The first table shows the relationship y=1/7x
The second table doesn't show a relationship due to (6,15)
The third table doesn't show a relationship due to (3,5)
The fourth table doesn't show a relationship due to (2,10)
So the first table is correct
"y varies directly as x" means y = kx
you do not know what k is yet, other than that it is some constant number.
Now plug in the given values, y=12 when x=4, in the equation
12 = 4k
=> k = 3
Now rewrite the equation with the k value you just found
y = 3k
Substitute 18 in place of x
y = 3(18)
y = 54
First you would have to isolate y.
3x - 3y = 18 -----> Subtract 3x from both sides
-3y = -3x + 18 --------> Now divide both sides by -3
y= x - 6
Now you replace the y with an f(x)
f(x) = x - 6
