The point at which the two lines intersect is (4,7).
The half life of a decaying substance is defined as the time at which the substance decreases to one-half of its original value. In this case, given hlf-life of 10 years and an original mass of 50 grams, after 10 years, the isotope mass becomes 50*0.5 or 25 grams. Answer is B.
Solve the equation by inserting 7 for x.
Our equation is now y=2.5(7)-1.5
Multiply.
Y=17.5-1.5
Subtract
Y=16
The answer is D. 16
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