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Mr. Martin’s math test, which is worth 100 points, has 29 problems. Each problem is worth either 5 points or 2 points. Let x be the number of questions worth 5 points and let y be the number of questions worth 2 points. x + y = 29, 5x + 2y = 100 How many problems of each point value are on the test? 10 problems worth 5 points and 25 problems worth 2 points 14 problems worth 5 points and 15 problems worth 2 points 16 problems worth 5 points and 13 problems worth 2 points 15 problems worth 5 points and 13 problems worth 2 points

2 Answers

3 votes

Answer:

14 problems worth 5 points and 15 problems worth 2 points

14 x 5 = 70

15 x 2= 30

70 + 30= 100

14+15 = 29 5 x 14 + 2 x 15=100

User Shane Delmore
by
8.1k points
2 votes

Answer:

Option 2.

Explanation:

Let x be the number of questions worth 5 points and let y be the number of questions worth 2 points.

Mr. Martin’s math test, which is worth 100 points, has 29 problems.


x+y=29 .... (1)


5x+2y=100 ..... (2)

Multiply equation (1) by 2.


2x+2y=58 .... (3)

Subtract equation (3) from equation (2), to eliminate the variable y.


5x+2y-(2x+2y)=100-58


5x+2y-2x-2y=42

Combined like terms.


(5x-2x)+(2y-2y)=42


3x=42

Divide both sides by 3.


x=14

The value of x is 14.

Substitute x=14 in equation (1).


14+y=29

Subtract 14 from both sides.


y=29-14


y=15

The value of y is 15.

It means 14 problems worth 5 points and 15 problems worth 2 points.

Therefore, the correct option is 2.

User Martin Wiboe
by
7.8k points

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