Answer:
A: 30
B: y=30x+14
Step-by-step explanation:
A
The rate of change, or slope, can be found from any two points (x1,y1) and (x2,y2), using the formula (y2-y1)/(x2-x1).
Let's use the points (0,14) and (2.2,80):
slope = (y2-y1)/(x2-x1)
= (80-14)/(2.2-0)
= 66/2.2
= 30
B
The slope-intercept form of a linear equation is y=mx+c, where x and y are any co-ordinates on the line, m is the slope and c is the y-intercept. Since we already know our slope (30), we can just plug this and some point on the line (eg (0,14)) into the equation to find c:
y=mx+c
14=(30)(0)+c
14=0+c
c=14
Therefore our equation is y=30x+14
