A. The equation that represents how much money Jane will have in total after saving for d days is: \[ J(d) = 100 + 5d \]
B. The equation that represents how much money Ellis will have in total after saving for d days is: \[ E(d) = 75 + 7d \]
C. The equation to find out how many days it will take for Jane and Ellis to have the same amount of money saved is: \[ 100 + 5d = 75 + 7d \]
D. After solving the equation from part C for d, you would find how much each will have saved at that time.
First, solve for d: \[ 100 + 5d = 75 + 7d \] \[ 100 - 75 = 7d - 5d \] \[ 25 = 2d \] \[ d = 12.5 \]
Now, substitute \( d = 12.5 \) back into either equation to find the amount they will have saved:
For Jane: \[ J(12.5) = 100 + 5(12.5) = 100 + 62.5 = 162.5 \]
For Ellis: \[ E(12.5) = 75 + 7(12.5) = 75 + 87.5 = 162.5 \]
Thus, after 12.5 days, Jane and Ellis each will have saved: \[ 162.5 \]