Question

PLEASE HELP MEH!!!! I CAN"T FIGURE THIS ONE OUT!!!!!



Steven recorded the growth of a plant over 10 wk for his science project. He made a graph that shows how much the plant grew each week. The plant was 2 in. tall when Steven started his project. At week 5, the plant was 8 in. tall. Complete the equation that represents Steven’s situation.
y=_____ x+_____

Answer 1

The answer is y = 1.2x + 2

x - the number of weeks
The equation is:    y = ax + b

He started the project when the plant was 2 in.
x = 0  (at the beginning, there were 0 weeks)
y = 2
y = ax + b
2 = a * 0 + b
2 = 0 + b
b = 2

At week 5, the plant was 8 in. 
x = 5
y = 8
b = 2

y = ax + b
8 = a * 5 + 2
8 = 5a + 2
8 - 2 = 5a
6 = 5a
a = 6/5 = 12/10 = 1.2

The equation is:
y = 1.2x + 2