To set up the system of equations based on the information provided:
a) Joelle's equation:
- Joelle currently has 18 rocks and gains 4 each week. The equation will be: \[ y = 4x + 18 \] So the answer for response areas is:
- Response area for slope: 4
- Response area for y-intercept: 18
b) Lewis's equation:
- Lewis currently has 30 rocks and gains 3 each week. The equation will be: \[ y = 3x + 30 \] So the answer for response areas is:
- Response area for slope: 3
- Response area for y-intercept: 30
Next, we need to find the number of weeks until Joelle and Lewis have the same number of rocks.
To do this, we set the two equations equal to each other:
\[ 4x + 18 = 3x + 30 \]
Solving for \( x \):
- Subtract \( 3x \) from both sides: \[ 4x - 3x + 18 = 30 \] \[ x + 18 = 30 \]
- Subtract 18 from both sides: \[ x = 30 - 18 \] \[ x = 12 \]
So, the answer for c) is:
- Response area for weeks: 12 weeks
Finally, we find out how many rocks each will have when they have equal collections. We can substitute \( x = 12 \) into either of the original equations. Using Joelle's equation:
\[ y = 4(12) + 18 \] \[ y = 48 + 18 \] \[ y = 66 \]
So, the answer for d) is:
- Response area for the number of rocks: 66 rocks
Therefore, the final formatted responses are:
a) Joelle has y = 4x + 18
b) Lewis has y = 3x + 30
c) After how many weeks will Joelle and Lewis have the same number of rocks in their collections? 12 weeks
d) How many rocks will Joelle and Lewis have when the amount of rocks in their collection is equal? They will each have 66 rocks in their collection.