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Law Incorporation [45]
3 years ago
15

Find the value of two numbers if their sum is 21 and their difference is 5

Mathematics
1 answer:
kykrilka [37]3 years ago
6 0

Answer: x = 13 and y = 8

Step-by-step explanation:

Two numbers must add to 21. We don't know them yet, so let's just use a placeholder for both of them for now.

x + y = 21

Their difference is five, meaning that if we subtract one from the other, we get five. Again, we don't know the numbers yet, so we'll add a placeholder for now.

x - y = 5

We can now solve a system of equations for x.

x = y + 5

y + 5 + y = 21

2y + 5 = 21

2y = 16

y = 8

x - 8 = 5

x = 13

So x = 13 and y = 8

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Vinvika [58]
1. m
2. One set of ordered pairs
3. b

To show why this is, I’m going to explain how to write the equation for a linear function with two random sets of ordered pairs - (1,0) and (5, 8).

First, find the slope. The formula for slope is m = (y2 - y1)/(x2-x1) where m is the slope and (x1, y1) and (x2, y2) are two sets of points.

This is why #1 is m. M is the letter used when finding slope.

To find m, I plug in the two sets of ordered pairs.

m = (8-0)/(5-1)
m = 8/4
m = 2

An equation for a line (linear function) is written in something called slope-intercept form. It looks like y = mx + b. m is the slope and b is the y-intercept (number y equals when x = 0). If m = 3 and b = 1, the equation would be y = 3x + 1.

Here, you have just solved for m and know it equals 2. Plug that value in for m.

y = 2x + b

To solve for b, plug one ordered pair in for x and y. I will use (1,0)

0 = 2(1) + b
0 = 2 + b
-2 = b

Now that you know b = -2, plug that in for b.
y = 2x - 2. Now you have the equation fo the line.
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3 years ago
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Answer:

Girls in Mr. Chang's class: 28 - 21 ; # girl students = # total students - # boy students ; 7 girl students.

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Pls helpp me on this
Crank

Answer:8

Step-by-step explanation:

When you round it depends on what number it is.

So for 7.8 it is closer to eight not seven

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