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Hitman42 [59]
3 years ago
12

Which expression is equivalent to 13 - -21

Mathematics
1 answer:
Ber [7]3 years ago
5 0
13 + 21 = 13- -21

The minus sign and negative cancel each other out.
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X+y+z=12<br> 6x-2y+z=16<br> 3x+4y+2z=28<br> What does x, y, and z equal?
lianna [129]

Answer:

x = 20/13 , y = 16/13 , z = 120/13

Step-by-step explanation:

Solve the following system:

{x + y + z = 12 | (equation 1)

6 x - 2 y + z = 16 | (equation 2)

3 x + 4 y + 2 z = 28 | (equation 3)

Swap equation 1 with equation 2:

{6 x - 2 y + z = 16 | (equation 1)

x + y + z = 12 | (equation 2)

3 x + 4 y + 2 z = 28 | (equation 3)

Subtract 1/6 × (equation 1) from equation 2:

{6 x - 2 y + z = 16 | (equation 1)

0 x+(4 y)/3 + (5 z)/6 = 28/3 | (equation 2)

3 x + 4 y + 2 z = 28 | (equation 3)

Multiply equation 2 by 6:

{6 x - 2 y + z = 16 | (equation 1)

0 x+8 y + 5 z = 56 | (equation 2)

3 x + 4 y + 2 z = 28 | (equation 3)

Subtract 1/2 × (equation 1) from equation 3:

{6 x - 2 y + z = 16 | (equation 1)

0 x+8 y + 5 z = 56 | (equation 2)

0 x+5 y + (3 z)/2 = 20 | (equation 3)

Multiply equation 3 by 2:

{6 x - 2 y + z = 16 | (equation 1)

0 x+8 y + 5 z = 56 | (equation 2)

0 x+10 y + 3 z = 40 | (equation 3)

Swap equation 2 with equation 3:

{6 x - 2 y + z = 16 | (equation 1)

0 x+10 y + 3 z = 40 | (equation 2)

0 x+8 y + 5 z = 56 | (equation 3)

Subtract 4/5 × (equation 2) from equation 3:

{6 x - 2 y + z = 16 | (equation 1)

0 x+10 y + 3 z = 40 | (equation 2)

0 x+0 y+(13 z)/5 = 24 | (equation 3)

Multiply equation 3 by 5:

{6 x - 2 y + z = 16 | (equation 1)

0 x+10 y + 3 z = 40 | (equation 2)

0 x+0 y+13 z = 120 | (equation 3)

Divide equation 3 by 13:

{6 x - 2 y + z = 16 | (equation 1)

0 x+10 y + 3 z = 40 | (equation 2)

0 x+0 y+z = 120/13 | (equation 3)

Subtract 3 × (equation 3) from equation 2:

{6 x - 2 y + z = 16 | (equation 1)

0 x+10 y+0 z = 160/13 | (equation 2)

0 x+0 y+z = 120/13 | (equation 3)

Divide equation 2 by 10:

{6 x - 2 y + z = 16 | (equation 1)

0 x+y+0 z = 16/13 | (equation 2)

0 x+0 y+z = 120/13 | (equation 3)

Add 2 × (equation 2) to equation 1:

{6 x + 0 y+z = 240/13 | (equation 1)

0 x+y+0 z = 16/13 | (equation 2)

0 x+0 y+z = 120/13 | (equation 3)

Subtract equation 3 from equation 1:

{6 x+0 y+0 z = 120/13 | (equation 1)

0 x+y+0 z = 16/13 | (equation 2)

0 x+0 y+z = 120/13 | (equation 3)

Divide equation 1 by 6:

{x+0 y+0 z = 20/13 | (equation 1)

0 x+y+0 z = 16/13 | (equation 2)

0 x+0 y+z = 120/13 | (equation 3)

Collect results:

Answer:  {x = 20/13 , y = 16/13 , z = 120/13

8 0
3 years ago
10
Archy [21]

Answer: 5h+9

Step-by-step explanation:

10h + (-5h)

5h+(6(+3))

6 0
2 years ago
A regression was run to determine whether there is a relationship between hours of tv watched per day(x) and number of sit-ups a
lisabon 2012 [21]

Answer:

17

Step-by-step explanation:

Given the regression model :

Y=ax+b

x = Hours of TV watched per day

y= number of sit-ups a person can do

A=-1.341

B=32.234

Y = - 1.341x + 32.234

Predict Y, when x = 11

Y = - 1.341(11) + 32.234

Y = −14.751 + 32.234

Y = 17.483

Hence, the person Cann do approximately 17 sit-ups

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3 years ago
A dealer paid 10000 for a boat at an auction. At the dealership, a salesperson sold the boat for 30% more than the auction price
Artist 52 [7]
Selling price of boat:  1.3($10,000) = $13,000.

Salesman's commission:  0.25($13000-$10000) = 0.25($3000) = $750
7 0
3 years ago
Number 3 pls 2 day of CMM pls help
STALIN [3.7K]

Answer:MODEL SOFTWARE ACCURACY

Brown & Sharpe 12.22.10 PC-DMIS 2.5+3.0L/1000 microns

Brown & Sharpe 7.10.7 PC-DMIS 1.9+4.0L/1000 microns

† Factory machine specification for accuracy: L = Length in mm of the feature to be checked Download CMM Linecard

Step-by-step explanation:

6 0
3 years ago
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