Everything except for 4 is correct, number 4 is c.
Step-by-step explanation:
8.3 = 8+ 0.3
= 8 + 3/10
= 8 3/10
Answer:
Part 1) 
Par 2) 
Part 3) 
Step-by-step explanation:
step 1
Find the 
we have

Remember that

therefore

step 2
Find the 
we know that

we have

substitute




square root both sides

we have that
---> given problem
so

step 3
Find the 
we know that

we have


substitute

Simplify

Answer:
x=7.48
Step-by-step explanation:
13^2+x^2=15^2
169+x^2=225
x^2=56
x=7.48