B. y = 7x
7x is the steady rate of 7 gallons per minute. The number of minutes can also be plugged into x to find the volume of the pool after x minutes.
17.5 because when you find range, you need to subtract the smallest number to the biggest number which in this case the biggest is 20 and smallest is 2.5.
The answer would be letter b
Linear functions have to have the same slope between any 2 points
find the slope betwen them
slope betwen 2 points (x1,y1) and (x2,y2) is
(y1-y1)/(x2-x1)
given
(1,12) and (3,9)
slope=(9-12)/(3-1)=-3/2
if we wanted to chek furthere, we check (3,9) and (5,6) and fnd that the slope is also -3/2
so
y=mx+b
m=slope
b=yint
y=-3/2x+b
find b
if x=1 then y=12
12=-3/2+b
add 3/2 both sides
12+3/2=b
13+1/2=b
26/2+1/2=b
27/2=b
y=-3/2x+27/2
try them
we have 2 x values
7 and 3
input them and see their outputs
for x=7
y=-3/2(7)+27/2
y=-21/2+27/2
y=6/2
y=3
(7,3) is a valid point
for x=3
hold a second, we already have a x=3
it is (3,9)
none of them
answer is (7,3)
