Which variable that single varible equation result in?
For that we have to study the given equations. For instance now in the above equations it is easy to talk about y in terms of x as the coefficient for y is (-1) [1 or -1 is numeriacally 1 and easy to handle] -4x-y = -6 —-(1) 4x+3y= 18 —-(2) From (1), we have y =6-4x —-* (taking -y to the other side and bringing -6 to this side and entire sides switching does not ask for sign change. What I mean is initially you get 6-4x = y which we write y= 6-4x) Putting * in (2), we get 4x + 3(6-4x) = 18 4x + (18 – 24x) = 18 —-(**) 4x + (-24x + 18) =18 (using additive commutativity) (4x-24x) + 18 = 18 (using additive associativity) -20x =0 (adding -18 to both the sides and using a+(-a) = 0 in other words canelling 18 additively on both the sides) Now (-20) X (what ) = 0 The answer is zero. So we have x= 0 And putting x= 0 in (*), y = 6-4x becomes y = 6- 4X0= 6 We have x = 0 and y= 6 Verification: Put x=0 and y=6 in (2) and check LHS = 4x + 3y = 4 X 0 + 3 X 6 = 0 + 18 = 18 = RHS which is corre
