Math, asked by 25morelsah, 3 months ago

Jake made a total of 7 copies at a copy shop, with some being black-and-white copies and some being color copies. Black-and-white copies cost 8 cents, and color copies cost 15 cents. If Jake spent a total of 70 cents on copies, which system of equations can be used to determine the number of black-and-white copies and the number of color copies he made? Assume b is the number of black-and-white copies and c is the number of color copies.
b + c = 7. 8 b + 15 c = 70.
b + c = 7. 15 b + 8 c = 70.
b + c = 70. 8 b + 15 c = 7.
b + c = 70. 15 b + 8 c = 7.

Answers

Answered by NIVEDHYT
2

Answer:

Jake spent a total of 70 cents.

b = black-and-white = 8 cents

c = color = 15 cents

70 = 8b + 15c

he made a total of 7 copies

b + c = 7

system of equation:

70 = 8b + 15c

b + c = 7

--------------------------

b + c = 7

b + c (-c) = 7 (-c)

b = 7 - c

plug in 7 - c for b

70 = 8(7 - c) + 15c

Distribute the 8 to both 7 and - c (distributive property)

70 = 56 - 8c + 15c

Simplify like terms

70 = 56 - 8c + 15c

70 = 56 + 7c

Isolate the c, do the opposite of PEMDAS: Subtract 56 from both sides

70 (-56) = 56 (-56) + 7c

14 = 7c

divide 7 from both sides to isolate the c

14 = 7c

14/7 = 7c/7

c = 14/7

c = 2

c = 2

---------------

Now that you know what c equals (c = 2), plug in 2 for c in one of the equations.

b + c = 7

c = 2

b + (2) = 7

Find b by isolating it. subtract 2 from both sides

b + 2 = 7

b + 2 (-2) = 7 (-2)

b = 7 - 2

b = 5

Jake made 5 black-and-white copies, and 2 color copies

hope this helps

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