Answer:
4 months
Step-by-step explanation:
-Let the number of months it takes for their heights to equal be x and let h(x) be the height after x months.
#For plant 1, we equate height after x months as:
[tex]h(x)=6+3x[/tex]
#For plant 2, we equate height after x months and at a constant rate m:
[tex]h(x)=2+mx[/tex]
#we equate and solve for rate of growth, m in plant 2 as below:
[tex]h(x)=2+mx\\\\but\ h(12)=50\\\\\therefore r=\frac{50-2}{12}\\\\r=4 \ inches/month[/tex]
#We then equate the two heights after x months to solve for x:
[tex]h(x)_1=h(x)_2\\\\6+3x=2+4x\\\\6-2=4x-3x\\\\x=4[/tex]
Hence, the plants have the same height after 4 months