So you will need to solve for x and y before evaluating 2x+y....

2x-y=9, y=2x-9 now this will make 4x^2-y^2=171 become:

4x^2-(2x-9)^2=171

4x^2-(4x^2-36x+81)=171

36x-81=171

36x=252

x=7, now we can use 2x-y=9 to solve for y...

2(7)-y=9

14-y=9

-y=-5

y=5

now we know that x=7 and y=5, 2x+y becomes:

2(7)+5

14+5

19

8 0

4 years ago

Carlos has 47 boxes that each have 10 markers. He gives 36 markers away.

r-ruslan [8.4K]

The answer is C. 434

5 0

3 years ago

Read 2 more answers

Rosa is attending an event where prizes are being given away. The probability of winning a T‐shirt is 0.89 and the probability o

vagabundo [1.1K]

Answer:

It is very likely that Rosa wins both prizes.

Step-by-step explanation:

The probability of winning a T‐shirt is 0.89 and the probability of winning a $20 gift certificate is 0.05. Which statement correctly describes the chances of Rosa winning a T‐shirt or a $20 gift certificate?

We have these three possibe outcomes.

Win t-shirt(0.89 probability) and lose the gift certiciate(1 - 0.05 = 0.95 probability)

Lose t-shirt(0.11 probability) and win the gift certiciate(0.05 probability).

Win both.

$p = 0.89*0.95 + 0.11*0.05 + 0.89*0.05 = 0.8955$

0.8955 = 89.55% probability of Rosa winning a T‐shirt or a $20 gift certificate, which is considered a very likely probability. So the answer is:

It is very likely that Rosa wins both prizes.

5 0

3 years ago