Aparent increases a child's allowance by 15 % each year. if the allowance is now $9, about how many years will it take for it to double? use the equation 18 9(1.15)^x. round to the nearest year.

5 years

Step-by-step explanation:

18= 9(1.15)^x

Divide each side by 9

18/9= 9/9 *(1.15)^x

2 = 1.15 ^x

Take the  log on each side

log (2) = log (1.15^x)

log 2 = x log 1.15

Divid each side by log (1.15)

log 2 / log 1.15 = x log 1.15/ log 1.15

log 2 / log 1.15 = x

4.959484455 = x

To the nearest year

5 years

step-by-step explanation:

let

we know that

the y-intercept is the y-coordinate of the point when the value of x is equal to zero

so

the y-coordinate of the point a is the y-intercept

the answer part a) is

the value of y-intercept is

part b) find the slope m

we know that

the value of the slope is equal to

substitute the values

therefore

the answer part b) is

the value of the slope is equal to

the general answer is

the slope is

the value of y-intercept is