<span>
<span>1st</span></span><span> formula 2n + 3m = 280
</span><span><span>
</span><span>2nd</span></span><span> formula 2n + 5m = 320
</span><span><span>
</span><span>rearrange 1st</span> formula to equal n:</span>
<span><span>2n = -3m + 280
</span>
</span><span>n = -3/2
m + 140
</span><span><span>
</span><span>rearrange 2nd</span> formula to equal n:</span>
<span><span>2n = -5m + 320
</span>
</span><span>n = -5/2m + 160
</span><span><span>
so now you have
</span>-3/2m + 140 = -5/2m + 160 </span>
<span><span>Rearrange to become:
</span>
</span><span><span>-3/2m + 5/2m = 160 - 140
</span>
</span><span>m = 20
</span><span>
</span>
<span>Now place 20 into the very 1st</span><span><span> equation in place
of the letter m
</span>
</span><span><span>2n + 3(20) = 280
</span>
</span><span><span>2n + 60 = 280
</span>
</span><span><span>2n = 220
</span>
</span><span>n = 110
</span><span><span>
</span>so it costs $110 per night, $20 per meal</span>
Hi there!
7 tenths times 10 is pretty easy and can be done on a calculator.
7 tenths is 0.7 in standard form.
0.7 × 10 = 7
Because if you think about it...
Tenths is like being dropped down by ten... then you multiply by ten which brings it back up to whole number seven. It may not make sense but that's what it is.
Hope this helps!
The answer is: [B]: " 3r − 5 " .
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H = 3r <span>− </span>5
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As you are looking for 1.75 minutes (or 105 seconds), the best thing to do is to find how many words she can type in 0.25 minutes (this is a quarter, and you can divide 1.75 by this). To find a quarter, you have to divide by 4, 120/4= 30. Therefore, every 15 seconds, Dorothy can type 30 words. As you've got 105 seconds, divide this by 15, and this gives you 7. Then multiply 30 by 7, and this gives you 210.
Dorothy can type 210 words in 1.75 minutes
Hope this helps :)
