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spin [16.1K]
3 years ago
13

Solve x2-14x+21=0 by completing the square

Mathematics
1 answer:
ankoles [38]3 years ago
4 0
x^2-14x+21=0\\\\x^2-2x\cdot7+7^2-7^2+21=0\\\\(x-7)^2-49+21=0\\\\(x-7)^2-28=0\\\\(x-7)^2=28\iff x-7=-\sqrt{28}\ \vee\ x-7=\sqrt{28}\\\\x=7-\sqrt{4\cdot7}\ \vee\ x=7+\sqrt{4\cdot7}\\\\x=7-2\sqrt7\ \vee\ x=7+2\sqrt7
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Ɪ ᴅᴏɴ'ᴛ ɢᴇᴛ ᴛʜɪs ᴄᴀɴ sᴏᴍᴇʙᴏᴅʏ ʜᴇʟᴘ ᴍᴇ ᴏɴ ᴛʜɪs ᴘʀᴏʙʟᴇᴍ ʀᴇᴀʟʟʏ ǫᴜɪᴄᴋ
Paraphin [41]
The answer would be reading

7 0
3 years ago
Read 2 more answers
Slope intercept form 3x-10y=-6
Anuta_ua [19.1K]

Answer:

y=3/10x+0.6

Step-by-step explanation:

3x-10y=-6

-3x        -3x

-10y=-3x-6

Divide -10 from everything.

y=3/10x+0.6

4 0
3 years ago
What is the average rate of change CAN SOMEONE PLEASE ANSWER THIS QUESTION I WILL BRAINLIEST
Andre45 [30]
<h3>Answer: The average rate of change for both is -2</h3>

=======================================================

Explanation:

The x interval [0,3] is the same as writing 0 \le x \le 3

It starts at x = 0 and ends at x = 3.

The graph shows that x = 0 leads to y = 3. So we have the point (0,3) on the parabola. We also have the point (3,-3) on the parabola.

Let's find the slope of the line through these endpoints.

(x_1,y_1) = (0,3) \text{ and } (x_2,y_2)  = (3,-3)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{-3 - 3}{3 - 0}\\\\m = \frac{-6}{3}\\\\m = -2\\\\

The slope is -2. This is the average rate of change from x = 0 to x = 3.

This is because:

slope = rise/run = (change in y)/(change in x) = average rate of change.

-------------

Now let's find the slope for the table.

Focus on the rows for x = 0 and x = 3. They lead to f(x) = 10 and f(x) = 4 respectively.

We have (0,10) and (3,4) as our two points this time.

(x_1,y_1) = (0,10) \text{ and } (x_2,y_2)  = (3,4)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{4 - 10}{3 - 0}\\\\m = \frac{-6}{3}\\\\m = -2\\\\

We get the same slope as before, so we have the same rate of change.

Notice the change in y (-6) is the same as before. So we could pick any two y values we want as long as there's a gap of 6 between them, and the second y value is smaller than the first.

3 0
2 years ago
Giant is selling Doritos 2 family bags for 7.00 I’m buying them for the class to celebrate great test scores if I buy 13 bags ho
elena55 [62]
$45.50
2 bags = $7
13 bags=?
7÷2=3.5
3.50=1 bag
$3.50 × 13 bags = $45.50 for 13 bags of Doritos
6 0
3 years ago
Evaluate a + b to the 2nd power for a = 2 and b = 3
jarptica [38.1K]

Answer:

25

Step-by-step explanation:

You add 2+3 and get 5. Then you square it to get 25.

4 0
3 years ago
Read 2 more answers
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