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Murljashka [212]

3 years ago

14

Patanna bought some red and blue bricks. She bought a total or 100 bricks. The red bricks cost $5 each and the blue bricks cost

$7 each. She spent a total of $560. How many red bricks and how many blue bricks did she buy?

1 answer:

klasskru [66]3 years ago

6 0

Let...

x=the number of red bricks

y=the number of blue bricks

Since she bought a total of 100 bricks... x+y=100.

Because the total cost is $560... 5x+7y=560.

Using these two equations, we can use the substitution method to solve for x and y.

x+y=100 ------------------------> x=100-y

subtract y on both sides

Because x=100-y...

this is x

5x+7y=560 (second equation) equals 5( 100 - y )+7y=560

This equation we created has only one variable so we can solve it.

5(100-y)+7y=560

500-5y+7y=560

2y+500=560

2y=60

y=30 blue bricks

Because x=100-y... x=100-30=70 red bricks.

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brainly.com/question/16863577

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