Ineed with
mark charged a battery. each minute, the percentage of the battery's capacity that was charged increased by 2.5. after 17 minutes of charging, the battery was 61.5 percent full.
how full was the battery when the charging began?
how long from the time that mark started charging did it take the battery to be fully charged?

The battery was 19 percent full

It will take 32.4 minutes for the battery to be fully charged

Step-by-step explanation:

Each minute, the percentage of the battery's capacity that was charged increased by 2.5

There is a constant increase for every minute, so m= 2.5

We use equation y = mx+b

After 17 minutes of charging, the battery was 61.5 percent full.

When x= 17 , y= 61.5. we know m = 2.5. solve for b

y=mx+b

61.5 = 2.5(17) + b

61.5 = 42.5 + b

Subtract 42.5 on both sides

b= 19

The battery was 19 percent full

To get full charge then y =100 percent

We plug in 100 for y and solve for x

y=mx+b , m= 2.5 , b=19

100=2.5x + 19

Subtract 19 on both sides

81= 2.5x

divide by 2.5 on both sides

x= 32.4

It will take 32.4 minutes for the battery to be fully charged

$12. that is my answer.