2
Because -
2 x 12=12
2 x 13 = 36
2 x 42 = 84
Answer:



Step-by-step explanation:
Given



From the rows, the equation is:
--- (1)
--- (2)
--- (3)
Make A the subject in: 

Substitute
in 


Make B the subject


Substitute
in 


Collect like terms


Divide by 9

Recall that:




Recall that:




Hence:



Answer : 2ab^3+4a^2b-5ab+5
Answer:
Step-by-step explanation: