Let f be the height of the fir trees
Let p be the height of the pine trees
We know from the problem that
f + p = 21 and 4f = 24 + p
rearrange the 2nd equation to get p = 4f - 24 and substitute into the other equation
so...
f + 4f - 24 = 21
5f - 24 = 21
5f = 45
f = 9 - height of the fir tree
substitute back into the 1st equation
9 + p = 21
p = 12 - height of the pine tree
Answer: Mrs.Buller collects a 500-ml sample of seawater for her chemistry class, and it has 1.94% of chlorine, we have to determine the amount of chlorine in the sample:
Therefore the chlorine content in 500ml of water is 9.7ml.
subtract 6 from the 21x+6. Then divide by 21. The answer is going to be -6/21
128/100=32/25
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