1. Colored copies cost 10¢ per copy and white copies
cost 5¢ per copy. Sandy made 400 copies, some of
which were colored and the rest white. Her total
bill was $22.50, How many colored copies and how
many white cepies did she make?

the answer is  A

Step-by-step explanation:i just did it

your welcome

350 white copies and 50 coloured copies

Step-by-step explanation:

$0.10 per coloured copy (c)

$0.05 per white copy (w)

$22.50 total bill

c = number of coloured copies

w = number of white copies

400 = number of total copies

Write a system of equations:

c + w = 400; c = 400 – w

0.1c + 0.05w = 22.5

Replace one variable in the more complex equation:

0.1(400 – w) + 0.05w = 22.5

Solve:

0.1(400 – w) + 0.05w = 22.5

40 – 0.1w + 0.05w = 22.5

40 – 0.05w = 22.5

–0.05w = 22.5 – 40

–0.05w = –17.5

w = –17.5 ÷ –0.05

w = 350

c = 400 – w

c = 400 – 116.7

c = 50

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.

y=x+9

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step-by-step explanation: