All three series converge, so the answer is D.
The common ratios for each sequence are (I) -1/9, (II) -1/10, and (III) -1/3.
Consider a geometric sequence with the first term <em>a</em> and common ratio |<em>r</em>| < 1. Then the <em>n</em>-th partial sum (the sum of the first <em>n</em> terms) of the sequence is
Multiply both sides by <em>r</em> :
Subtract the latter sum from the first, which eliminates all but the first and last terms:
Solve for 
:
Then as gets arbitrarily large, the term 
will converge to 0, leaving us with
So the given series converge to
(I) -243/(1 + 1/9) = -2187/10
(II) -1.1/(1 + 1/10) = -1
(III) 27/(1 + 1/3) = 18
Answer:
x = 12z + 1 and y = 10z - 1
Step-by-step explanation:
To solve the system of equations, we can use the substitution method
If we call
3x - 4y + 4z = 7 I
x - y - 2z = 2 II
2x - 3y + 6z = 5 III
Clearing II x = 2 + y + 2z
Now, replacing II in III
2(2 + y + 2z) - 3y +6z = 5
4 + 2y + 4z - 3y + 6z = 5
10z - y = 1 from here y = 10z - 1
Finally, replacing y in I
3x - 4(10z - 1) + 4z = 7
3x -40z + 4 + 4z = 7
3x - 36z = 3
3x = 36z + 3
x = 12z + 1
Done
Answer:
x = 11
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
sum the 3 angles and equate to 180
5x + 4 + 6x - 3 + 4x + 14 = 180 ← collect like terms on left side
15x + 15 = 180 ( subtract 15 from both sides )
15x = 165 ( divide both sides by 15 )
x = 11
Answer:
i have no idea what to do
Step-by-step explanation:
