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3 years ago

Find cos in the triangle There are 2 pictures

Mathematics

1 answer:

Elanso [62]3 years ago

7 0

Answer is c

something that helps me is
soh- opposite hypotenuse cah - adjacent and hypotenuse toa- opposite and adjacent
soh cah toa

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14, 16, and 20 using elimination method showing work. Thanks so much

Nady [450]

14) x=0, y=3, z=-2

Solution Set (0,3,-2)

16) x=1, y=1 and z=1

Solution set = (1,1,1)

20) x = -263/31, y=164/31 ,z=122/31

Solution set (-263/31, 164/31 ,122/31)

Step-by-step explanation:

14)

$x-y+2z=-7\\y+z=1\\x=2y+3z$

Rearranging and solving:

$x-y+2z=-7\,\,\,eq(1)\\y+z=1\,\,\,eq(2)\\x-2y-3z=0\,\,\,eq(3)$

Eliminate y:

Adding eq(1) and eq(2)

$x-y+2z=-7\,\,\,eq(1)\\ 0x+y+z=1\,\,\,eq(2)\\-------\\x+3z=-6\,\,\,eq(4)$

Multiply eq(2) with 2 and add with eq(3)

$0x+2y+2z=2\,\,\,eq(2)\\\\x-2y-3z=0\,\,\,eq(3)\\--------\\x-z=2\,\,\,eq(5)$

Eliminate x:

Subtract eq(4) and eq(5)

$x+3z=-6\,\,\,eq(4)\\x-z=2\,\,\,eq(5)\\-\,\,\,+\,\,\,\,\,\,-\\---------\\4z=-8\\z= -2$

So, value of z = -2

Now putting value of z in eq(2)

$y+z=1\\y+(-2)=1\\y-2=1\\y=1+2\\y=3$

So, value of y = 3

Now, putting value of z and y in eq(1)

$x-y+2z=-7\\x-(3)+2(-2)=-7\\x-3-4=-7\\x-7=-7\\x=-7+7\\x=0$

So, value of x = 0

So, x=0, y=3, z=-2

S.S(0,3,-2)

16)

$3x-y+z=3\\\x+y+2z=4\\x+2y+z=4$

Let:

$3x-y+z=3\,\,\,eq(1)\\x+y+2z=4\,\,\,eq(2)\\x+2y+z=4\,\,\,eq(3)$

Eliminating y:

Adding eq(1) and (2)

$3x-y+z=3\,\,\,eq(1)\\x+y+2z=4\,\,\,eq(2)\\---------\\4x+3z=7\,\,\,eq(4)$

Multiply eq(1) by 2 and add with eq(3)

$6x-2y+2z=6\,\,\,eq(1)\\x+2y+z=4\,\,\,eq(3)\\---------\\7x+3z=10\,\,\,eq(5)$

Now eliminating z in eq(4) and eq(5) to find value of x

Subtracting eq(4) and eq(5)

$4x+3z=7\,\,\,eq(4)\\7x+3z=10\,\,\,eq(5)\\-\,\,\,-\,\,\,\,\,\,\,\,\,\,-\\-----------\\-3x=-3\\x=-3/-3\\x=1$

So, value of x = 1

Putting value of x in eq(4) to find value of x:

$4x+3z=7\\4(1)+3z=7\\4+3z=7\\3z=7-4\\z=3/3\\z=1$

So, value of z = 1

Putting value of x and z in eq(2) to find value of y:

$x+y+2z=4\\1+y+2(1)=4\\1+y+2=4\\y+3=4\\y=4-3\\y=1$

So, x=1, y=1 and z=1

Solution set = (1,1,1)

20)

$x+4y-5z=-7\\3x+2y+2z=-7\\2x+y+5z=8$

Let:

$x+4y-5z=-7\,\,\,eq(1)\\3x+2y+2z=-7\,\,\,eq(2)\\2x+y+5z=8\,\,\,eq(3)$

Solving:

Eliminating z :

Adding eq(1) and eq(3)

$x+4y-5z=-7\,\,\,eq(1)\\2x+y+5z=8\,\,\,eq(3)\\---------\\3x+5y=1\,\,\,eq(4)$

Multiply eq(1) with 2 and eq(2) with 5 and add:

$2x+8y-10z=-14\,\,\,eq(1)\\15x+10y+10z=-35\,\,\,eq(2)\\----------\\17x+18y=-49\,\,\,eq(5)$

Eliminate y:

Multiply eq(4) with 18 and eq(5) with 5 and subtract:

$54x+90y=18\\85x+90y=-245\\-\,\,\,-\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,+\\-------\\-31x=158\\x=-\frac{263}{31}$

So, value of x = -263/31

Putting value of x in eq(4)

$3x+5y=1\\3(-\frac{263}{31})+5y=1\\-\frac{789}{31}+5y=1 \\5y=1+\frac{789}{31}\\5y=\frac{820}{31}\\y=\frac{820}{31*5}\\y=\frac{164}{31}$

Now putting x = -263/31 and y=164/31 in eq(1) and finding z:

We get z=122/31

So, x = -263/31, y=164/31 ,z=122/31

Solution set (-263/31, 164/31 ,122/31)

Keywords: Solving system of Equations

Learn more about Solving system of Equations at:

#learnwithBrainly

4 0

2 years ago

10 divided by 2 <br> 8 times 3<br> 54 minus 6<br> 9 to the third power

musickatia [10]

Answer:

10 divided by 2 is 5

8 times 3 is 24

54 minus 6 is 48

9 to the third power is 729

Step-by-step explanation:

5 0

3 years ago

Lana has $15 for dinner her meal is $13.90 she wants to leave a 18% tip does she have enough explain your answer

denis-greek [22]

Start off by finding 18% of 13.90.

18%=18/100=0.18

0.18(13.9)=2.5

An 18% tip would be $2.50.

Now, to find out if Lana has enough money, add $2.50 to $13.90 to find out the total amount she would leave. You get $16.40. Since $16.40>$15, the answer is no because the total cost including the 18% tip is greater than $15.

3 0

3 years ago

You have a coupon for $5 off your total bill at Mama's Meals on Main a. How much will you pay after using the coupon if your bil

HACTEHA [7]

Answer :

(a) Amount paid after using the coupon = $b - $5 = $(b-5)

(b) Amount paid = $23.45 - $5 = $(23.45-5) = $18.45

Amount paid = $54.83- $5 = $(54.83-5) = $49.83

Step-by-step explanation :

As we are given that:

Amount of coupon = $5

If amount of total bill = $b

Now we have to calculate the amount paid after using the coupon.

Amount paid after using the coupon = Total amount of bill - Amount of coupon

Amount paid after using the coupon = $b - $5 = $(b-5)

Now we have to calculate the amount paid if bill was $23.45.

Amount paid after using the coupon = Total amount of bill - Amount of coupon

Amount paid = $23.45 - $5 = $(23.45-5) = $18.45

Now we have to calculate the amount paid if bill was $54.83.

Amount paid after using the coupon = Total amount of bill - Amount of coupon

Amount paid = $54.83- $5 = $(54.83-5) = $49.83

6 0

3 years ago

One card is randomly selected from a deck of cards find the odds against drawing a seven

Stella [2.4K]

Answer:

$\frac{3}{4}$

Step-by-step explanation:

Probability of getting a 7 + Probability of not getting a 7 = 1.

Odds against drawing a 7 = Probability of not getting a 7.

We could calculate the probability of getting a 7 and subtract 1 from it to get the answer.

There a four sevens in a deck of card, one of each kind.

Probability of getting a 7 = $P(7) = \frac{4}{52} = \frac{1}{13}$

$\implies P(not \hspace{1mm} getting \hspace{1mm} a \hspace{1mm} 7) = 1 - P(7)$

$\implies$ P(not getting a 7) $= 1 - \frac{1}{13} = \frac{12}{13}$

4 0

3 years ago