Answer:
zero
Step-by-step explanation:
I. xy + 2y=3 Not linear equation because is grade 2 equation (xy).
II. x-2y = y Are linear equations in two unknowns (x and y).
III. 3x + 2y = 5 Are linear equations in two unknowns (x and y).
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Corect ansver: C) II and III only</h2><h2>
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Answer:
4
Step-by-step explanation:
Since the base is the same, 3, you can just get rid of it using the principles of log. What you're left with is:
2x + 1 = x + 5
Now just solve for x:
2x - x = 5 - 1
x = 4
The answer is 42! hope this helps!
One way of doing it is by using the properties of summing things, like factoring out the minus sign:
<span><span>∑<span>n=2</span>8</span><span>−(n−5)</span>=−<span>∑<span>n=2</span>8</span><span>(n−5)
</span></span>
and splitting it up into two parts and again factor
<span>=−<span>(<span><span>∑<span>n=2</span>8</span><span>n−5<span>∑<span>n=2</span>8</span>1</span></span>)
</span></span>
The last sum is just counting how many numbers there are from 2 to 8, which is 7 (you can do it on your fingers). The first one can be calculated fast if we are clever and use this identity:
<span><span>∑<span>n=1</span>m</span>n=<span><span>m(m+1)</span>2
</span></span>
So what we get is
<span><span>=−<span>(<span>−1+<span><span>8(8+1)</span>2</span>−7</span>)</span>=8−72/2=8−36=−28.</span></span>
