Answer:
Could you give more info so I can try and sole it?
Step-by-step explanation:
C = # of carpenter hrs , b = # of blacksmith hrs
c + b = 30...c = 30 - b
20c + 25b = 690
20(30 - b) + 25b = 690
600 - 20b + 25b = 690
-20b + 25b = 690 - 600
5b = 90
b = 90/5
b = 18 <== hrs worked as blacksmith
c + b = 30
c + 18 = 30
c = 30 - 18
c = 12 <== hrs worked as carpenter
Answer:

Step-by-step explanation:

Multiply by 10 on both sides,

so 
Answer:d
Step-by-step explanation: just factor it out
The mnemonic SOH CAH TOA helps you remember that
... Sin = Opposite/Hypotenuse
The side opposite angle K is marked with length 5. The hypotenuse KM is marked with length 10. Using the above relationship ...
... sin(∠K) = 5/10 = 1/2
The first choice is appropriate: 