Answer:
12 months
Step-by-step explanation:
Let
x ----> the number of months
y ----> Felicia's height in centimeters
we know that
The linear equation in slope intercept form is equal to
[tex]y=mx+b[/tex]
where
m is the rate or slope
b is the y-coordinate of the y-intercept (initial value)
In this problem we have that
[tex]m=3.5\ \frac{cm}{month}[/tex]
[tex]b=80\ cm[/tex]
substitute
[tex]y=3.5x+80[/tex]
In how many months will she be 122 cm tall?
For y=122 cm
substitute the value of y in the linear equation and solve for x
[tex]122=3.5x+80[/tex]
subtract 80 both sides
[tex]3.5x=122-80[/tex]
[tex]3.5x=42[/tex]
[tex]x=12\ months[/tex]
