Answer:
15
Step-by-step explanation:
Rate of change or slope or gradient of a line passes two points (x1, y1) and (x2, y2) could be calculated by:
(y2 - y1)/(x2 - x1)
=> Rate of change of the line passing (1,15) and (3,45):
(45 - 15)/(3 - 1) = 30/2 = 15
Answer:
parallel: -1/2
perpendicular: 2
Step-by-step explanation:
lines that are parallel have the same slope because they never intersect
lines that perpendicular, have the opposite reciprocal slope.
y = mx + b
where m is the slope
y = -1/2x + 6
-1/2 is the slope.
the slope in the equation given: -1/2
the slope parallel to the line given : -1/2
the slope perpendicular : opposite reciprocal, so the opposite of -1/2 is 1/2 and the reciprocal of 1/2 is 2.
Answer:

Step-by-step explanation:
I am assuming that you mean (4,−9) and (8, -3).

Hope this helps.
Answer:
Step-by-step explanation:
(51 miles)/(3 gal) = 19 miles/gal