-7.8
The rest can be solved as rational. Negative numbers are not rational.
Answer:
Katherine need to work minimum 10 hours lifeguarding to meet her requirements
Step-by-step explanation:
Given:
Rate for Lifeguarding = 
Rate for walking dogs = 
She had worked 2 hours walking dog
Money for walking dogs = Rate for walking dogs
hours worked=
she can work a maximum of 15 total hours and must earn at least $160.
Let hours required for lifeguarding be x
Money for life guarding = Rate for walking dogs
hours worked for lifrguarding= 
Total Money she must earn = Money for lifeguarding + Money for walking dogs

Rounding to nearest hour
Katherine need to work minimum 10 hours lifeguarding to meet her requirements
AB is horizontal. The slope of a horizontal line is zero.
120+120=240
The roof of the house is 240 ft^2
Use a=

r^2 (r represents your radius of 4 feet)

(4^2)
Answer = 16

^2