Which equations support the fact that rational numbers are closed under addition?

Simplify the expression 8x-2x+12x-3

aev [14]

Answer:

18x - 3

Step-by-step explanation:

Add all the X values

8x + -2x + 12x = 18x

Put the final numbers on the side.

-3

18x-3

7 0

2 years ago

What is the mean of 5,9,6,6,11,8,4

____ [38]

Answer:

7

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

Find all pairs of natural numbers which can be the solution to the equation a+b=42.

Setler [38]

Answer:

(1,41), (2,40), (3,39), (4,38), (5,37), (6,36), (7,35), (8,34), (9,33), (10,32), (11,31), (12,30), (13,29), (14,28), (15,27), (16,26), (17,25), (18,24), (19,23), (20,22), (21,21), (22,20), (23,19), (24,18), (25,17), (26,16), (27,15), (28,14), (29,13), (30,12), (31,11), (32,10), (33,9), (34,8), (35,7), (36,6), (37,5), (38,4), (39,3), (40,2), (41,1).

Step-by-step explanation:

To find all pairs of natural numbers which are solution to a+b=42, we need to first choose a value to one of them (let's choose 'a'), and that value will be the lowest possible, so we begin with a=1, and then we increase to 2, and 3, and so on.

For each value of a, we calculate the value of b using the equation.

So, starting with a=1, we have that b=41

Then, with a=2, we have that b=40, and so on.

Doing this until a=41 (so b=1 will be the lowest value possible for b), we have the pairs of natural number we want:

(1,41), (2,40), (3,39), (4,38), (5,37), (6,36), (7,35), (8,34), (9,33), (10,32), (11,31), (12,30), (13,29), (14,28), (15,27), (16,26), (17,25), (18,24), (19,23), (20,22), (21,21), (22,20), (23,19), (24,18), (25,17), (26,16), (27,15), (28,14), (29,13), (30,12), (31,11), (32,10), (33,9), (34,8), (35,7), (36,6), (37,5), (38,4), (39,3), (40,2), (41,1).

5 0

2 years ago

A, B, and C are collinear B is between A and C.

mixas84 [53]

Answer:

x = 7

Step-by-step explanation:

A, B, and C are collinear B is between A and C.

AC = AB + BC

2x + 1 = x + 4 + 2x - 10

2x + 1 = 3x - 6

2x - 3x = - 6 - 1

- x = - 7

x = 7

5 0

3 years ago

Josue leans a 26-foot ladder against a wall so that it forms an

postnew [5]

Answer:

25.61 feet

Step-by-step explanation:

First, we can draw a picture (see attached picture). With the wall representing the rightmost line, and the ground representing the bottom line, the ladder (the hypotenuse) forms a 80 degree angle with the ground and the wall and ground form a 90 degree angle.

Without solving for other angles, we know one angle and the hypotenuse, and want to find the opposite side of the angle.

One formula that encompasses this is sin(x) = opposite/hypotenuse, with x being 80 degrees and the hypotenuse being 26 feet. We thus have

sin(80°) = opposite / 26 feet

multiply both sides by 26 feet

sin(80°) * 26 feet = opposite

= 25.61 feet as the height of the wall the ladder reaches

6 0

2 years ago