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3 years ago

Substitute -3x-8y=4 -2x+7y=15

1 answer:

3 0

-2x=15-7y
x=-7.5+3.5y

-3x-8y=4
-3(7.5+3.5y)-8y=4
-22.5-10.5y-8y=4
-22.5-18.5y=4
-18.5y=4+22.5
-18.5y=26.5
y=-53/35

the fraction might not be in lowest terms.

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4 years ago

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almond37 [142]

Answer:

Step-by-step explanation:

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3 years ago

72 is 60% of what number? Enter your answer in the box.

Sindrei [870]

Do cross-multiplication

72/x = 60/100 

so 

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5 0

4 years ago

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A gumball machine contains 300 grape flavored balls, 400 cherry flavored balls, and 500 lemon flavored balls. What is the probab

Svet_ta [14]

Answer:

Pr(of getting 1grape ball, 1 cherry ball and 1 lemon ball) =0.20832

Step-by-step explanation:

Let the grape falvored ball be represented by G,

Cherry flavored balls be C

Lemon flavored balls be L

the possible order of picks for getting 1grape ball, 1 cherry ball and 1lemon ball are; GCL or GLC or CGL or CLG or LGC or LCG

Pr(of getting 1grape ball, 1 cherry ball and 1 lemon ball)

= Pr(GCL) or Pr(GLC) or Pr(CGL) or Pr(CLG) or Pr(LGC) or Pr(LCG)

with replacement we have;

Probability = $\frac{number of required outcomes}{number of possible outcomes}$

= $\frac{300}{1200}*\frac{400}{1200}*\frac{500}{1200} +\frac{300}{1200}*\frac{500}{1200}*\frac{400}{1200} +\frac{400}{1200}*\frac{300}{1200}*\frac{500}{1200} \\ \\+\frac{400}{1200}*\frac{500}{1200}*\frac{300}{1200} +\frac{500}{1200}*\frac{300}{1200}*\frac{400}{1200} +\frac{500}{1200}*\frac{400}{1200}*\frac{300}{1200}$

= 0.03472 + 0.03472 +0.03472 + 0.03472 + 0.03472 + 0.03472

=0.20832

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3 years ago

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damaskus [11]

We have a work problem right here. We can use knowledge on ration and proportion to answer this type of problem. We do as follows:

1 job / 2 hours + 1 job / 3 hours = 1 job / time it takes for both when working together

time it takes for both when working together = 1.2 hours

4 0

4 years ago

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