A group of 5 friends is out to dinner. Each of the friends will order the dinner special, and they have a coupon for $10 off the entire bill. Which equation can be used to find the total cost of
all the dinners after the coupon is applied?
10d - 5 = 0
100 + 5 = 0
5d + 10 = 0
5d - 10 = 0

I NEED HELP BUT I DONT HAVE THE FREE TRIAL THING

Acable company wants to provide cell phone service for residents on an island. the function for the cost of laying the cable from the island to the mainland is c(x)= 6.500 square root x2+4, where x represents the length of the cable in feet. what are the domain and range of the function? a) domain: all real numbers range: all real numbers greater than or equal to 17,000 b) domain: all real numbers greater than or equal to 0 range: all real numbers greater than or equal to 17,000 c) domain: all real numbers greater than or equal to 0 range: all real numbers greater than or equal to 13,000 d) domain: all real numbers greater than or equal to 13,000 range: all real numbers greater than or equal to 0

Find a number such that if you add 8 and divide the result by 4 you will get the same answer as if you subtracted 3 from the original number and divided by 2

Icould really use some with this question.