Answer:
she has 12 - D quarters.
She has 24 (12-D) cents in quarters
Step-by-step explanation:
You know that the number of coins, and you know the number of dimes - even if the amount is a variable - you can find the amount of quarters with an equation.
If you knew that Lina had 6 dimes instead of D, you would say 12 - 6 and get the number of quarters. You can do the same thing here.
and If you know Lina has 6 quarters, you could find the amount of money in cents by multiplying 6 by 25. You can do that here too, but with variables and an equation.
My teacher taught me a simple equation for these types of problems:
(percent of solution × amount of solution) + (percent of solution × amount of solution) = (percent of solution × total amount of solution)
in simple terms: %amount + %amount = %total amount
We know don't know how much gallons of 60% solution we need so it will be represented as x. We dont know the total amount either so it would have to be both solutions added together so 50 + x. Now lets solve:
(0.60)(x) + (0.24)(50) = (0.50)(50 + x) simplify/ distribute
0.6x + 12 = 25 +0.5x get all xs on one side and numbers on other
0.1x + 12 = 25
0.1x = 13 divide both sides by 0.1 to find x
x = 130
You need 130 gallons of 60% solution.
Answer:
Ellis Island doctors were particularly watching for signs of contagious diseases. Incurable diseases included trachoma and tuberculosis and guaranteed a return trip to where the immigrant came from.”
Step-by-step explanation:
