Answer:
5,470 mg
Step-by-step explanation:
108 minutes is 4 half-lives:
<u> Time</u> <u> Lead</u>
<u> Min.</u> <u>mg Pb</u>
0 87520
27 43760
54 21880
81 10940
108 5470
She needs 15 cans of varnish
Step-by-step explanation:


Subtract equation ( ii ) from equation ( i ) :
Remember that the sign of each term of the second expression changes i.e equation ( i ) now becomes -4x -3y = -20


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Again , Substituting the value of y in equation ( ii ) :
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Hope I helped ! ツ
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C is your answer.
It contains the proper points and form. A is not in point-slope form and B has the incorrect slope.