All categories

3 years ago

If the nth term of a number sequence is 5n– 2n, find the first 3 terms and the 10th term.

Mathematics

1 answer:

rewona [7]3 years ago

6 0

To answer this question, you need to subtitute a number for each n. First find the first and then push off of there.

You might be interested in

Tia measured the daily high temperature in Kats, Colorado for each of the 30 days in April. She then created both a dot plot and

lara31 [8.8K]

*see attachment below showing the dot plot and box plot created by Tia

Answer:

Dot plot

Step-by-step explanation:

In a dot plot, the temperature of a day is represented by 1 dot. There are 30 dots on the box plot shown in the attachment that was made by Tia.

This dot plot display makes it easier to find how many days had a temperature that is higher than 15°.

Thus, from the dot plot, we have:

2 dots representing 2 days having a temperature of 16°C each

2 days also have daily temperature of 17°C

2 days have temperature of 18°C as well, and

1 day has temperature of 19° C.

Therefore, the number of days that had a temperature above 15°C is 7 days.

3 0

3 years ago

Read 2 more answers

For which value of b can the expression x2 + bx + 18 be factored?

Dmitry_Shevchenko [17]

Answers:

b = -19
b = -11
b = -9
b = 19
b = 11
b = 9

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

Explanation:

Here are all the ways to multiply to 18 when using integers only:

-1*(-18) = 18
-2*(-9) = 18
-3*(-6) = 18
1*18 = 18
2*9 = 18
3*6 = 18

Sum each pair of factors to find out a possible value of b.

-1 + (-18) = -19
-2 + (-9) = -11
-3 + (-6) = -9
1 + 18 = 19
2 + 9 = 11
3 + 6 = 9

Therefore, the possible values of b are

b = -19
b = -11
b = -9
b = 19
b = 11
b = 9

which are the final answers.

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

An example:

Let's say b = 11. This would mean $x^2+bx+18$ becomes $x^2+11x+18$

It would factor to $(x+2)(x+9)$ since it was stated earlier that:

2+9 = 11

2 * 9 = 18

You can use the FOIL rule, distributive property, or the box method to confirm that $x^2+11x+18 = (x+2)(x+9)$ is a true equation for all real numbers x.

This same idea applies for the other values of b.

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

If you're curious why this works, consider multiplying the two factors (x+p) and (x+q)

Use the FOIL rule to get $(x+p)(x+q) = x^2+qx+px+pq = x^2+(p+q)x + pq$

The middle term $(p+q)x$ has the components add to the coefficient, while those same two components multiply to get the last term. This is why when factoring we're looking for two numbers that multiply to 18, and also add to the value of b (which in the case of the last example was 11).