Question 54545
TO SOLVE BY THE SUBTRACTION METHOD YOU NEED TO BE ABLE TO ELIMINATE ONE OF THE VARIABLES THUS MULTIPLY THE FIRST EQUATION BY 1/9 & MULTIPLY THE SECOND EQUATION BY -3/7 THIS RESULTS IN THE FOLLOWING EQUATONS:

(1/9)(3/7)X+(1/9)(5/9)Y=(1/9)27   &
(-3/7)(1/9)X+(-3/7)(2/7)=(-3/7)7  NOW WE ADD THESE TWO EQUATIONS
-----------------------------------------------
0X+(5/81)Y+(6/49)Y=3-3 OR Y(5/81)+(6/49)=0 OR Y=0

SUBSTITUTING Y=0 IN EITHER EQUATION WE SOLVE FOR X THUS

(3/7)X+0=27 OR 3X=27*7 OR 3X=189 OR X=63
PROOF USING THE OTHER EQUATION WE GET
(1/9)63=7 OR 63/9=7 OR 7=7