Answer:
y=-3/4x+8
y=5
Step-by-step explanation:
M represents the slope of the line, i.e. the rate of change,. This means that since the candle shrinks; i.e. the size decreases, we make out rate of change negative. We then see that the candle shrinks by 3/4 of an inch per hour (rate of change) this is the numerical part of our m. This leaves us with a final m of -3/4.
B represents the y-intercept. The candle is 8 inches before we begin burning thus 8 is out y-intercept because at time 0 the candle is 8 inches tall.
To solve for the height after 4 hours you just need to plug 4 in for x, since the rate of change is in inches per hour.
y=-3/4(4)+8
y=5