{3x+2y=-5 {4x-3y= -18

1 answer:

3 0

$\left\{\begin{array}{ccc}3x+2y=-5&|\cdot3\\4x-3y=-18&|\cdot2\end{array}\right\\\\\underline{+\left\{\begin{array}{ccc}9x+6y=-15\\8x-6y=-36\end{array}\right}\qquad\text{add both sides of the equations}\\\\.\qquad17x=-51\qquad|:17\\.\qquad x=-3\\\\\text{put the value of x to the first equation}\\\\3(-3)+2y=-5\\-9+2y=-5\qquad\text{add 9 to both sides}\\2y=4\qquad\text{divide both sides by 2}\\y=2\\\\Answer:\ \boxed{x=-3\ and\ y=2}$

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Geometry question. please help

Vinvika [58]

Answer:

The length of PQ is 18 feet.

The length of PR is 18 feet.

The length of QR is 24 feet.

Step-by-step explanation:

A way to set an equation up for this problem is:

$\frac{4}{3}x+x+x=60$

where x is the three lengths of the isosceles triangle, but the base QR is 4/3 the length of the other two congruent sides, length PQ and PR. The 60 represents the total length of the perimeter.

Then, solve for x from the equation, and you’ll get x=18. But your not done yet. Since the variable x in the equation stands for the sides of the isosceles triangle, so plug 18 into the equation and it should look like this:

$\frac{4}{3}(18)+18+18=60$

Don’t solve the whole equation, just solve the $\frac{4}{3}(18)$ part of the equation, which is equal to 24. So the final equation is this:

$24+18+18=60$

Conclusion: 24 is the length of QR, and 18 is the length of PQ and PR. And they all equal 60, which is the perimeter. This is very true because the length of PQ and PR are the same (length 18), since it’s an isosceles triangle, and the length of QR is 4/3 the length of PQ and PR (4/3 of 18= 24).

Sorry for the long explanation.

But hope this helps and answers your question :)

8 0

3 years ago

How to find the value of a+b+c given that a=4,b=3 and c= -2

Alexus [3.1K]

Answer: 5

Step-by-step explanation: 4 + 3 + -2 = 5

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3 years ago

The probability of drawing a heart from a standard deck of cards is 0.25. You record the car do you draw and return the car befo

Licemer1 [7]

Answer: C) 0.112

Step-by-step explanation:

In binomial distribution with parameters n (Total trails) and p (probability of getting success sin each trial) , the probability of getting success in x trials is given by :-

$P(X=x)=^nC_xp^x(1-p)^{n-x}$

Given : The probability of drawing a heart from a standard deck of cards is 0.25

Here , getting heart is the success.

Then p= 0.25

For n= 20

The probability that you will draw a heart seven times i.e. x= 7:

$P(X=7)=^{20}C_7(0.25)^7(1-0.25)^{20-7}$

$P(X=7)=\dfrac{20!}{7!(20-7)!}(0.25)^7(1-0.25)^{20-7}\ \ [\because\ ^nC_r=\dfrac{n!}{r!(n-r)!}]$

$=\dfrac{20\times19\times18\times17\times16\times15\times14\times13!}{7!13!}(0.25)^7(0.75)^{13}\\\\=77520(0.00006103515625)(0.0237572640181)\\\\=0.112406195476\approx0.112$