Answer:
(a)Equation representing amount of lights on Monday is 2 x  + 3 y = 44
(b)Equation representing amount of lights on Tuesday is 5 x  + 3 y = 56
 (c) Bob uses 4 stands of light on Bushes
     and Bob uses 12 strands of lights on trees.
Step-by-step explanation:
Let x = strands of lights on bushes.
Let y = strands of lights on trees.
Bob used 44 strands of light to decorate 2 bushes and 3 trees on Monday.
So, the number of light on 2 bushes  = 2x 
and  the number of light on 3 tress  = 3 y 
⇒ 2 x  + 3 y = 44
Also, On Tuesday, Bob used 56 strands of lights to decorate 5 bushes and 3 trees.
So, the number of light on 5 bushes  = 5x 
and  the number of light on 3 tress  = 3 y 
⇒ 5 x  + 3 y = 56
Now, solving the system of equations:
2 x  + 3 y = 44
5 x  + 3 y = 56
Subtract equation (2) from (1), we get
2 x  + 3 y  - (5 x  + 3 y)  = 44   - 56
or, 2x - 5x = - 12
or, 3x  =  12 ⇒ x =  12/3  = 4    or x  = 4
Using x  = 4 in 2x + 3y = 44
2(4)  + 3y  =  44
or, 3y = 44- 8 = 36
or y = 36 /3 = 12 or y  = 12
So, the value of x  = 4, and y = 12
Hence, here Bob uses 4 stands of light on Bushes
and Bob uses 12 strands of lights on trees.