Answer:
Substitute in the values of both given coordinates & form 2 equations:

Find the value of B from the equation 2A - B = 1:

Substitute in the B-value to the other equation:

Find the B-value using the equation from before:
Therefore the equation Ax + By = 1 would equal:

5 is your answer
1: 5 = 5: 25
Note that the colon can act like a fraction.
Simplify 5/25.
(5/25)/(5/5) = 1/5 = 1/5
5 is your answer
hope this helps
The answer would be X =90