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2 years ago

Solve by substitution

Mathematics

1 answer:

Hunter-Best [27]2 years ago

7 0

Answer:

Step-by-step explanation:

y = -9 ------(1)

9x -4y = -9 -------(2)

substitute (1) into (2)

9x - 4 (-9) = -9

9x = - 45

x = -5

there you go, x = -5 and y = -9

so. (-5 , -9 )

hope this helps

please mark it brainliest

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Prove the identity.<br>cosx sin (x+y) - sinx cos(x+y) = siny

Jet001 [13]

Answer:

In the explanation

Step-by-step explanation:

Going to start with the sum identities

sin(x+y)=sin(x)cos(y)+sin(y)cos(x)

cos(x+y)=cos(x)cos(y)-sin(x)sin(y)

sin(x)cos(x+y)=sin(x)cos(x)cos(y)-sin(x)sin(x)sin(y)

cos(x)sin(x+y)=cos(x)sin(x)cos(y)+cos(x)sin(y)cos(x)

Now we are going to take the line there and subtract the line before it from it.

I do also notice that column 1 have cos(y)cos(x)sin(x) in common while column 2 has sin(y) in common.

cos(x)sin(x+y)-sin(x)cos(x+y)

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6 0

3 years ago

Kendra needs 1 dollar to buy a ball she has 73 cents what coins does she need to add her 73 cents

Alexeev081 [22]

Answer:

Kendra needs 3 coins (1 coin of 25 cent & 2 coins of 1 cent) to add 27 cents in 73 cents to make 1 dollar

Step-by-step explanation:

Given :

Kendra has 73 cents

She need 1 dollar to by a ball

∴ She requires additional money = $1\ dollar - 73 \ cents = 27 \ cents$

Standard Coins available are 50 cents , 25 cents, 10 cents, 5 cents and 1 cent.

To make 27 cents = $25+1+1$ = 1 coin of 25 cent & 2 coins of 1 cent

5 0

3 years ago

How do you do 3 through 4

Furkat [3]

#3 is not a function because there are two answers for one out put

#4 is a function because it is a straight line

8 0

3 years ago

Jill estimated she would spend $50.00 a month on clothing. However, at the end of the year she discovered she actually spent $71

RideAnS [48]

50$ per month for 12 years would mean she spent only (50 x 12) 600$ per year.

She actually spent $711, her forecast was off target by (600-7111) $111.

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5 0

2 years ago

Brian spends 3 5 of his wages on rent and 1 3 on food. If he makes £735 per week, how much money does he have left?

Margarita [4]

Answer :

Brian has $49 left.

Step by step explanation :

Step 1 : Find how much money Brian spends on rent and food.

First question we should be asking is what is 3/5 of 735?

Let's find that.

$\frac{3}{5}$ * $\frac{735}{1}$

= $\frac{(3)(735)}{(5)(1)}$

= $\frac{2205}{5}$

= 441

We know Brian spends $441 on rent. Now we find how much he spends on food.

$\frac{1}{3} * \frac{735}{1}$

= $\frac{(1)(735)}{(3)(1)}$

= $\frac{735}{3}$

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Brian spends $245 on food.

Step 2 : Add what he spends on rent and food together.

$441 + $245 = $686

Step 3 : To find out how much money Brian has left, we subtract $686 from $735.

$735 - $686 = $49

Conclusion : Brian has $49 left.

Hope this helps, please mark brainliest if possible. Have a nice day.

3 0

2 years ago