Answer:
Since the legs of the right triangle measure x + 1 and x + 15, respectively, and since the hypotenuse measures x + 17, the Pythagorean Theorem can be used as follows: (x + 1)2 + (x + 15)2 = (x + 17)2. This equation becomes (x2 + 2x + 1) + (x2 + 30x + 225) = x2 + 34x + 289, which then becomes 2x2 + 32x + 226 = x2 + 34x + 289. When all the terms are moved to one side, the equation becomes x2 – 2x – 63 = 0, and when the left side of the equation is factored, it becomes (x – 9)(x + 7) = 0. At this point, it seems as if x can equal 9 or –7, but if x were –7, one of the legs would have a negative length, and this is impossible. For this reason x equals 9, and the legs of the triangle measure 10 and 24, respectively, while the hypotenuse measures 26. Since cosine is
length of adjacent leg
length of hypotenuse
, the cosine of angle C is
24
26
, or
12
13
.
Answer:
f(x) = (3x -2)(2x +1)
Step-by-step explanation:
The procedure for factoring expression of the form ...
ax² +bx +c
is to look for factors of a·c that have a sum of b.
The product a·c is 6·(-2) = -12. You are looking for factors that have a sum of b = -1. From your familiarity with multiplication tables, you know ...
-12 = 1(-12) = 2(-6) = 3(-4)
The sums of the factor pairs in this list are -11, -4, -1. So, the last pair of factors, {3, -4} is the one we're looking for.
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At this point, there are several ways to proceed. Perhaps the simplest is to rewrite the linear term as the sum of terms involving these factors:
-x = 3x -4x
f(x) = 6x² +3x -4x -2
Now, the expression can be factored 2 terms at a time:
f(x) = (6x² +3x) -(4x +2) . . . . . pay attention to signs
f(x) = 3x(2x +1) -2(2x +1) . . . . factor each pair
f(x) = (3x -2)(2x +1) . . . . . . . . factor out the common factor of (2x+1)
Using m = (y2-y1)/(x2-x1)
(2-3)/(4-2)
-1/2
The slope is -1/2. b.
The mean is 250.875.
Using this information, I can put the following into a calculator:
√(((250.875-195)²+(250.875-358)²+(250.875-201)²+(250.875-276)²+
(250.875-161)²+(250.875-301)²+(250.875-387)²+(250.875-128)²)÷8)
Which equals:
87.9878
This is the standard deviation of the MP3 players.
Answer:
i think the correct answer of these qusion is `B´
