The equation for the height of the first plant is y = x + 20 and for the second plant is y = 2x + 5. To find when the two plants reach the same height, we need to set the two equations equal to each other and solve for x:
x + 20 = 2x + 5
Subtracting x from both sides, we get:
20 = x + 5
Subtracting 5 from both sides, we get:
15 = x
Therefore, it will take 15 weeks for the two plants to reach the same height. The correct answer is 15.
Petunia bought two plants. She placed the first plant, which was 20 inches tall, on the windowsill. She noticed that the plant was growing at the rate of 1 inch per week.
y = x + 20
She placed the second plant, which was 5 inches tall, on the coffee table. She noticed that it was growing at the rate of 2 inches per week.
y= 2x + 5
The heights of the two plants are shown in the graph below.
How many weeks will it take for the plants to reach the same height?
5
20
10.
15
1 answer