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3 years ago

When doing substitution what is the answer for -9x+2y=228, -7x-1=y

Mathematics

2 answers:

tiny-mole [99]3 years ago

8 0

Answer:

do u need to solve for x

Step-by-step explanation:

anyanavicka [17]3 years ago

7 0

Answer: x = -10, y = 69

Step-by-step explanation:

-9x+2y=228 -------------- eqn,. 1

-7x-1=y ---------------- eqn. 2

from eqn. 2 make y subject formula i.e.

y = -7x -1

substitute for y in eqn. 1

-9x + 2(-7x-1) = 228

-9x -14x - 2 = 228

collect like terms

-23x = 228 + 2

-23x = 230

x = 230/-23

x = - 10

substitute for x in eqn. 2

y =-7(-10) -1

y = 70-1

y = 69

Hence, x = -10, y = 69

kindly rate brainliest

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avanturin [10]

Answer:

10.5

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2 years ago

Q. A customer wants to re-carpet a living room andhallway. You charge $5.99 per square yard toremove old carpet and $4.50 per sq

Tanzania [10]

Living Room Area = 17.5 x 20 = 350 sq ft

Hall Area = 4 x 12 = 48 sq. ft.

Total area of carpeting: 340 + 48 = 398 sq. ft.

We need to convert total area in sq ft to sq yd. The conversion ratio is

1 sq ft = 0.11 sq yd

So, 398 sq ft would be:

398 * 0.11 = 44.22 sq yd.

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Removing rate would be:

44.22 * 5.99 = $264.88

Assuming you gotta install both carpet and pad,

Carpet + pad = 16.99 + 3 = 19.99 per sq yd.

You gotta buy for 44.22 sq yd.

So, it will cost (carpet):

44.22 * 19.99 = $883.96

Installing rate 4.50 per sq yrd, so to carpet 44.22 sq yd, would need:

4.50*44.22 = $198.99

Assuming carpet is provided by installation guys, total charge:

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11 months ago

Wich algebraic expression represents ”forty times a number”?<br><br> 40+n<br> 40n<br> n-40<br> 40/n

Reika [66]

The answer to the problem is 40n

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3 years ago

Read 2 more answers

(15) ? Is this correct or am I missing something, thanks :)

svetoff [14.1K]

You are correct!

Step 1:Write what you know
Madeline's Height: 6 ftMadeline's Shadow: 108 in
Friend's Height: X (we use X as a variable because his height is unknown)Friend's Shadow: 108 in - 1.5 ft 108 in - 18 in 90 in
Step 2:Set up proportions
6 x----- = -----108 90
Step 3:Cross Multiply & Solve
108x = 540x = 5 ft tall

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2 years ago

In the game of roulette, a player can place a $8 bet on the number 17 and have a StartFraction 1 Over 38 EndFraction probabili

svp [43]

Answer:

Expected value of the game: -$0.421

Expected loss in 1000 games: $421

Step-by-step explanation:

There are two possible outcomes for the event:

- There is a 1 in 38 chance of winning $280

- There is a 37 in 38 chance of losing $8

The expected value for a single game is:

$E(X) = \frac{1}{38}*\$280-\frac{37}{38}*\$8\\E(X)=-\$0.421$

The expected value of the game is -$0.421

In 1,000 plays, the expected loss is:

$L = 1,000*-\$0.421\\L=-\$421$

You would expect to lose $421.

3 0

2 years ago