Question

in a cave a stalactites gets 4 millimeters longer each year.this year it is 72 centimeters longhow many years until it is 1 meter long

Answer 1

in a cave a stalactites gets 4 millimeters longer each year.this year it is 72 centimeters long

how many years until it is 1 meter long​

we have that

the linear equation that represent this situation is equal to

y=4x+720

where

y ------> length in mm

x ----> number of years

Remember that

72 cm=720 mm

so

For y=1 m ------> y=1,000 mm

substitute in the equation

1,000=4x+720

4x=1,000-720

4x=280

x=70 years

therefore

answer is 70 years