I need to do this problem by completing the square . help please

Mathematics

1 answer:

sukhopar [10]3 years ago

8 0

Answer:

the roots are n = 1 + √15 and n = 1 - √15

Step-by-step explanation:

In this case I would immediately rewrite n² - 2n - 5 = 10 as

n² - 2n = 10 + 5 = 15.

To complete the square: Identify the coefficient of n (it is -2). Halve that, obtaining -1, square this result, and then add the outcome (1) to and subtract the outcome (1) to n² - 2n:

n² - 2n + 1 - 1 = 15

Next, rewrite n² - 2n + 1 as the square of a binomial:

(n - 1)² = 15

Finally, take the square root of both sides:

n - 1 = ±√15

so that the roots are n = 1 + √15 and n = 1 - √15

You might be interested in

A King in ancient times agreed to reward the inventor of chess with one grain of wheat on the first of the 64 squares of a chess

maxonik [38]

Answer:

Total weight of the wheat placed on 45th square will be = $1.26\times 10^{6}tons$

Step-by-step explanation:

King rewarded the inventor of chess by giving grain of wheat on every square of the chess board. He places one grain of wheat on first square, 2 on second, 4 on 3rd, 8 on 4th and so on.

In fact he places grains of wheat in a progression S = 1, 2, 4, 8, 16.........n terms where value of n is 64.

We can rewrite the progression as S = 2°, 2, 2², 2³,.........n terms (n = 64)

In a geometric progression we know the nth term = $a(r^{n-1})$