Answer:
A
Step-by-step explanation:
ΔACD is similar to ΔBCD by AA similarity theorem
AD/AC = BD/BC
x/5 = 4.2/6
6x = 21
x = 3.5
Hope this helps! ;)
Answer:
First mechanic worked 20 hours and second mechanic worked 5 hours
Step-by-step explanation:
Let the number of hours the first mechanic worked = 
Let the number of hours the second mechanic worked = 
Therefore, we can write 2 equations and then solve them simultaneously:


Rearranging the first equation: 
and substituting into the second equation to find
:


Now sub
into the first equation to find 

Therefore, first mechanic (a) worked 20 hours and second mechanic (b) worked 5 hours
10
Therefore, the greatest common factor of 30 and 50 is 10.