Explain the advantages of using substitution to solve the system of equations instead of elimination: X= 6+ y
48=2X+ 2Y

The correct answer is: x=15 and y=9

Complete step by step solution:
In the substitution method, we need to work only on one equation, instead of
two equations.
We need only a few steps to solve since we have only 1 equation.

Let x = 6 + y…(i)

and 48 = 2x + 2y….(ii)
On substituting (i) in (ii), we get

                                      48 = 2(6 + y) + 2y

                                     ⇒ 48 = 12 + 2y + 2y

                                      ⇒ 48 = 12 + 4y

                                      ⇒ 48 -12 = 4y

                                     ⇒ 36 = 4y

                                     ⇒4y =36

                                      ⇒ y = 9
On substituting the value of y in (i), we get

                                        x = 6 + 9

                                        ⇒ x = 15
Hence we get x = 15 and y = 9