Answer:
y= 35/2 when x=5
x=6 when y =21
Proportinal relatiionships: y=−x
, y=15x
Step-by-step explanation:
The formula for direct variation is
y= kx
If y=7 and x=2, we can solve for k
7 =k*2
Divide by 2
7/2 =k
y =7/2 x
Now if x=5
y =7/2 * 5
y =35/2
Now if y=21
21 =7/2 * x
Multiply by 2/7
21 * 2/7 = 7/2 * 2/7 x
6 =x
Which equation represents a proportional relationship?
y=−x
YES k = -1 Some people debate about having a negative constant, but everything I have read and taught says you can have a negative constant.
y=−5(x+1)
This does not go through the origin so no
if x=0 y = -5
y = 5x + 1
if x = 0 y =1 so no
y=15x
YES k = 15