You have to fraw sticks as the 10's for example #2 prtend thise are the sticks.(I)
IIII 4 tens in 42 the circles as ones O O SO,IIII00
Answer:
D
Step-by-step explanation:
if u said 5x=30 then its D
Answer:
a) -7/9
b) 16 / (n² + 15n + 56)
c) 1
Step-by-step explanation:
When n = 1, there is only one term in the series, so a₁ = s₁.
a₁ = (1 − 8) / (1 + 8)
a₁ = -7/9
The sum of the first n terms is equal to the sum of the first n−1 terms plus the nth term.
sₙ = sₙ₋₁ + aₙ
(n − 8) / (n + 8) = (n − 1 − 8) / (n − 1 + 8) + aₙ
(n − 8) / (n + 8) = (n − 9) / (n + 7) + aₙ
aₙ = (n − 8) / (n + 8) − (n − 9) / (n + 7)
If you wish, you can simplify by finding the common denominator.
aₙ = [(n − 8) (n + 7) − (n − 9) (n + 8)] / [(n + 8) (n + 7)]
aₙ = [n² − n − 56 − (n² − n − 72)] / (n² + 15n + 56)
aₙ = 16 / (n² + 15n + 56)
The infinite sum is:
∑₁°° aₙ = lim(n→∞) sₙ
∑₁°° aₙ = lim(n→∞) (n − 8) / (n + 8)
∑₁°° aₙ = 1
Solve simultaneously.
4x - y = 8
6x + y = 2
Multiply top equation by 6, and bottom equation by 4, to eliminate x, so that we can find y.
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24x - 6y = 48
24x - 4y = 8
Subtract top from bottom to form one equation.
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-2y = 40
Therefore y is 20.
Put y back in to an equation, such as 4x - y = 8.
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4x - 20 = 8
4x = 28
x = 7
