You can use the desmos matrix calculator online! it’s a lot of help
-8a-3b+6b-5a+9b= -13a-18b
-8a-5a=-13a
3b+6b+9b=18b
Hopes that helps
It costs 1.75$ for 250 envelopes. each one of the envelopes cost 0.007$
<h3>
Answer: 6 dollars per kilogram</h3>
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Explanation:
The mixed number 4 & 1/2 converts to the decimal form 4.5
The unit price is 27/(4.5) = 6 dollars per kilogram
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If you wanted, you can think of it like this ratio
4.5 kg : 27 dollars
Dividing both parts of that ratio by 4.5 will lead to
1 kg : 6 dollars
