Question

what is the total amount due for all utilities?
monthly utilities
electricity: $0.13/kwh, usage 5,500 kwh, amount due $715.00
water: $0.06/10 gal, usage 9,000 gallons, amount due $54.00
gas: $1/100 cubed ft, usage 4,800 cubed feet, amount due $48.00
phone lines: $40/line, usage 3 lines, amount due $120.00
international minutes: $0.10/minute, usage 70 minutes, amount due $7.00
internet service: $180/month, flat charge per month, amount due $180.00

Explanation:

Step1: Sum up all amount due

Add the amount due for each utility: $715 + 54+48 + 120+7+180$

Step2: Calculate the sum

$$\begin{align*} &715+54 + 48+120+7+180\\ =&(715+54)+48+(120+7)+180\\ =&769+48 + 127+180\\ =&(769+48)+(127+180)\\ =&817+307\\ =&1124 \end{align*}$$

Answer:

$1124.00$