Solve the simultaneous equation for x and y

Question

ax + by = 48ab

ax - by = 2ab

 

can you please show working out. 

Thank you!!!

Answer 1

  

ax + by = 48ab   (1)

ax - by = 2ab      (2)  

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You can add (2) to (1),  term-by-term on both sides, to eliminate "by" completely:

 

2ax + 0by = 50ab

 

Now solve this for x (it will be in terms of ab on the right hand side), then substitute back into (1) or (2) for x so you can solve for y.   Another option would be to subtract (2) from (1) to eliminate "ax" then solve for y.