B. 2h+4
"Worked four hours MORE"
More symbolizes addition
"TWICE the number of hours"
Twice means multiple by two - two times a number
1. $49.05
2. $23.40
3. $88.55
4. $81.13
5. $155.25
6. $189.75
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.
a.129.6+16.2
= 145.8
b.129.6×16.2
= 2099.52
c.129.6÷16.2
= 8
d.129.6−16.2
= 113.4
e.192.4+14.8
= 207.2
