Exercises
1. the sum of both numbers of a number is 14. on having exchanged the numbers of the tens with that of the units, the number increases in 18. it finds the original number.
2. the sum of two numbers is 21 and his difference is 5. ¿which are the numbers?
i am grateful for them to him very much indeed : )

Adiverr from the university of florida women’s swimming and diving team is competing in the ncaa zone b championships

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

How many times larger is 6 × 10^12 than 2 × 10^7? a. 30,000 b. 3,000 c. 3,000,000 d. 300,000