What is the answer to this 3a-b;a=4b=6

What is the value of x in the following equation. -x ^3/2 = -27

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.

Liang bought a basket of apples to make pies for her friends. the basket of apples weighed p pounds. before she had time to make the pies, she ate 3 pounds of apples. there are 17 pounds of apples left to make pies.