9514 1404 393
Answer:
970
Step-by-step explanation:
It turns out that the radical terms cancel, so the result is an integer. You can find the integer value using your calculator. It is ...
(5 +2√6)³ +1/(5 +2√6)³ = 970
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The cube of 'a' is ...
(5+2√6)³ = 5³ +3·5²·2√6 +3·5·(2√6)² +(2√6)³
= 125 +3·50√6 +3·120 +48√6
a³ = 485 +198√6
The reciprocal of this is ...
b³ = 1/a³ = 1/(485 +198√6) = (485 -198√6)/(485² -6·198²) = (485 -198√6)/1
b³ = 485 -198√6
Then the sum is ...
a³ +b³ = (485 +198√6) +(485 -198√6) = 970
l = 2w - 4
Because we're solving for 2l + 2w, that can be simplified to
2(2w - 4) + 2w = 34
4w - 8 + 2w = 34
6w - 8 = 34
6w = 42
w = 7
Knowing this, we can input w:
2(7) + 2l = 34
14 + 2L = 34
2l = 20
l = 10
L = 10, W = 7, Option C
P² - 12 p - 13 = 0
Δ = ( -12)² - 4 ( 1 * - 13)
Δ = 144 + 52
Δ = 196 = 14²
x₁ = (- ( -12) + 14 ) / 2 = 26/2 = 13
x₂ = ( - ( -12) - 14) /2 = - 2 /2 = - 1
S = 13
Answer:
B. 
Step-by-step explanation:
