*PLEASE SOLVE USING EQUATIONS* Lea spent half of her weekly allowance playing mini-golf. To earn more money her parents let her wash the dog for $8.20. What is her weekly allowance if she ended with $16.40?

A) $16.40
B) $24.60
C) $17.22
D) $4.10

Aiden drives to school and back each day. the school is 16 miles from his home. he averages 40 miles per hour on his way to school. if his trip takes 1 hour, at approximately what speed does aiden drive home?

The longer leg of a 30° 60° 90° triangle is 16 times square root of three how long is a shorter leg

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.