Manny has two part-time jobs. She earns $21 per hour (a) working as an aerobics instructor, and $12.50 per hour (d) working at the donut shop. Her earnings are represented by the expression 21a+12.50d

. How much money will she earn working 4 hours as an aerobics instructor and 8 hours at the donut shop?(1 point)

1 answer

To find out how much Manny will earn working 4 hours as an aerobics instructor and 8 hours at the donut shop, we can substitute \(a = 4\) and \(d = 8\) into the expression \(21a + 12.50d\).

So, we calculate:

\[ 21(4) + 12.50(8) \]

Calculating each part:

  1. For the aerobics instructor: \[ 21 \times 4 = 84 \]

  2. For the donut shop: \[ 12.50 \times 8 = 100 \]

Now, we sum the two amounts:

\[ 84 + 100 = 184 \]

Thus, Manny will earn $184 working 4 hours as an aerobics instructor and 8 hours at the donut shop.