Answer:
7 hours
Step-by-step explanation:
Step one:
given data
let the total charges be y and the number of hours be x
Company A charges
$60 reservation fee plus another $15 per hour.
so
y=60+15x----------1
Company B charges
$25 reservation fee plus another $20 per hour
y=25+20x------------2
Step two:
equate the 2 expressions above we have
60+15x=25+20x
collect like terms
60-25=20x-15x
35=5x
divide both sides by 5
x= 35/5
x= 7 hours
Answer:
30 gallons of 20% acid solution should be mixed.
Step-by-step explanation:
Let x gallons of a 20% acid solution was mixed with 30 gallons of a 40% solution, to obtain a mixture of 30% acid solution.
Therefore, final volume of the solution will be (x + 30) gallons.
Now concept to solve this question is
20%.(x) + 40%.(30) = 30%.(x + 30)
0.20(x) + 0.40(30) = 0.30(x + 30)
0.20x + 12 = 0.30x + 9
0.30x - 0.20x = 12 - 9
.10x = 3
x =
x = 30 gallons
Therefore, 30 gallons of the 20% acid solution should be mixed.
Pemdas
Parentheses
Answer: -11