Question

How do I work this using the substitution method?
x-y=3
x+2y=-3

Answer 1

Answer :





Given two equations are -




x-y=3 (a)




x+2y=-3 (b)





To find ,



values of x and y





Main solution :




In the first equation x - y = 3





From this ,




x = y + 3 ( i )




We know the other linear equation in x and y is

x + 2y = - 3





Now , substituting the value of x from (i) in this equation , we get :




y + 3 + 2y = -3




Now solving for y using transposition :




3y + 3 = -3




3y = -6




y = -2




Now putting the value of y in equation (a) to find the value of x




x - ( - 2 ) = 3




x + 2 = 3




x = 1



Therefore ,




Value of x = 1 and Value of y = -2