Solve the following system of equations by elimination :
X - 4Y = - 8
3X + 4Y = 0

The correct answer is: x = - 2 and y = 3 over 2

Complete step by step solution:

Let x-4y = - 8…(i)

and 3x + 4y = 0…(ii)
On adding (i) from (ii),
we get LHS to be x - 4y + 3x +  4y = x + 3x = 4x
and RHS to be - 8 + 0 = - 8
On equating LHS and RHS, we have 4x = - 8

                                     ⇒x = - 2
On substituting the value of x in (i), we get - 2 - 4y = - 8

                                   ⇒ - 4y = - 8 + 2

                                    ⇒ - 4y = - 6

                                    ⇒ y =
Hence we get x = - 2 and y =
Note: We can also solve these system of equations by making the coefficients of x
to be the same in both the equations.