Answer:
n = (123 - 3a) / 0.1
Step-by-step explanation:
Given:
3a + 0.1n = 123
Solve for n
3a + 0.1n = 123
Subtract 3a from both sides
3a + 0.1n - 3a = 123 - 3a
0.1n = 123 - 3a
Divide both sides by 0.1
n = (123 - 3a) / 0.1
The resulting equation if 3a + 0.1n = 123 is solved for n is n = (123 - 3a) / 0.1
Amount of fuel in the tank before the story begins . . . . . zero.
Total amount poured in . . . . . 3/4 gallon.
Total amount burned:
on Friday . . . . . 1/4 gallon
on Sunday . . . . 1/4 gallon
Total used . . 1/2 gallon .
Amount remaining in the tank on Monday:
(3/4 gallon in) - (1/2 gallon burned) = 1/4 gallon left.
==> NOT empty
The tank would have been empty on Monday IF Becky
had poured in only 1/2 gallon, instead of 3/4 of a gallon
before the first flakes began to fly.
So... the radiator has 15 liters of 70% antifreeze.. but needs an 80% antifreeze
well, so, you need to drain some and put some with higher percentage, seems to be, you will end up at the same 15 liters, possible the radiator's capacity, of 80% antifreeze
so, the same amount going out, of 70% is the same amount going in, of 100% antifreeze
now.. let's use the decimal format for the percents, or 70% is 70/100 or 0.7 and so on
so.. let's subtract, from the current solution, 0.7x and add 1x or x, our antifreeze concentration amount, should be 12 though
10.5 - 0.7x + x = 12
solve for "x"
Answer:
the answer is option D. 25 units. I hope that you'd understand