Answer:
5. 9 8. 
Step-by-step explanation:
a²+b²=c²
so for #5 12²+b²=15²
144+b²=225 (subtract 144 from both sides)
b²=81
b=9
For #8
9²+b²=11²
81+b²=121 (subtract 81 from both sides)
b²=40
b=
=

I only see a black image, can you resend the image? or type it out here
Answer:
3/10
Step-by-step explanation:
Subtract the sum of 1/3, 4/15 and 1/10 from 1:
10/30 + 8/30 + 3/30 = 21/30, or 7/10
Then: 1 - 7/10 = 3/10