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Mathematics

1 answer:

Andrei [34K]2 years ago

6 0

Answer:

X=17

Step-by-step explanation:

7x-1+5x-23=180

12x-24=180

12x=204

x=17

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Please help Explanation will be appreciated thanks,

Genrish500 [490]

Answer: A; 6.3%

Step-by-step explanation:

Problem 1

For the first problem, we first want to find y so that we can plug it into the expression.

We can use elimination method for the system of equations to solve.

3x+3y=21

3x-y=5

We subtract both equations to eliminate x.

4y=16 [divide both sides by 4]

y=4

Now that we know y, we can plug it into the expression.

$\frac{4}{2} -3$ [divide]

$2-3$ [subtract]

$-1$

We know that the answer is A.

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Problem 2

For the second problem, we need to know how to calculate percent error. The formula for precent error is $\frac{|measured-exact|}{exact} *100%$ . We know that the exact value is 80 because the buyer was supposed to given 80. 75 is the measured value because that was what the buyer was given.