Question

A bean plant grows at a constant rate for a month. After 10 days, the plant is

35 centimeters tall. After 20 days, the plant is 55 centimeters tall.

Which equation models the height of the plant, y, after x days?

A. y+35 = 2(x+10)

B. y - 35 = 2(x - 10)

C. y - 10 = 2(x - 35)

D. y - 35 = 1/2 (x - 10)​

Answer 1

the answer is B

Explanation:

Answer 2

B. y - 35 = 2(x - 10)

Explanation:

The height of the plant, y, after x days could be modeled by the equation

y-y0=k(x-xo) (1),

where y0 was the initial height at 'x0'th. day, and k is the constant of proportionality.

From equation (1), k could be evaluated as follows:

k=(y-y0)/(x-x0)

From the problem statement, we may determine k by plugging in the given values, e.g. y0= 35, x0=10, y=55, x=20.

Thus,

k=(55-35)/(20-10)=2

Therefore, the model equation becomes

y-35=2(x-10)