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4 years ago

Can someone help me with this

Mathematics

1 answer:

CaHeK987 [17]4 years ago

5 0

Answer:

19 m

Step-by-step explanation:

This is Geometric progression with

$\left \{ {{u_1=1,\: u_2 =2} \atop {u_n=2^{n-1}u_1} \right.$

Then the fomular of sum is

$S=u_1\frac{2^n-1}{2-1} =1\times(2^n-1)=2^n-1\\To\: save\: 1 \:million\: then \; our \:sum \: will \: be\: 1000000\\Hence,\\2^n-1=1000000\\2^n=1000001\\n=log_{2}{1000001}\approx19,9\\Thus, it\:would \;be \:19 \:months \:before\: we\: saved \:1000000 \:pounds$

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Answer: k = -1 +/- √769

<u>Step-by-step explanation:</u>

48x - ky = 11

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$\frac{48}{k}$ and $-\frac{(k + 2)}{16}$ are perpendicular so they have opposite signs and are reciprocals of each other. When multiplied by its reciprocal, their product equals -1.

$-\frac{(k + 2)}{16}$ * $\frac{k}{48}$ = -1

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