To find out how much money Jacqueline will earn this week from her two jobs, we can evaluate the expression \( 15l + 12s \) using the values \( l = 5 \) (hours worked as a lab assistant) and \( s = 7 \) (hours worked as a cashier).
Now, substitute the values into the expression:
\[ 15l + 12s = 15(5) + 12(7) \]
Calculating each term:
- \( 15(5) = 75 \)
- \( 12(7) = 84 \)
Now, add these two results together:
\[ 75 + 84 = 159 \]
Thus, Jacqueline will earn $159 this week from her two jobs.