Answer:
-31
Step-by-step explanation:
a - 8x will change to (-7) - 8(3) = -31
Speed boat departed 1.75 hrs after steam boat1.8 hrs after speed boat departure, steam boat has sailed for a total: 1.8+1.75 = 3.55 hrssteam boat's speed is 36.8 km/hr, so it has traveled: 3.55*36.8 = 130.64 km
speed boat is 86.9 km behind steam boat. so it is 130.64-86.9 = 43.74 km from portspeed boat's speed = 43.74/1.8 = 24.3 km/hr
You would add up the percentages first, which would bring everything up to 35%. You would then take the original cost of the item, which is $30 and multiple it by the 35%.
The equation would look like...
30 x .35 =
This will give you $10.50, which isn't the final answer.
You would then subtract 10.50 from the $30 that was asked for at the beginning by the retailer.
Your final answer is $19.50. :) Which isn't a bad deal if I say so myself.