tolong jawab ya.. makasih...

2/3ₓ - 1/4y = 5 dan 7/6ₓ+3/2y=1                    | 8x-3y=60
--------------------------------------------ₓ₁₂             | 8(6)-3y=60
8ₓ-3y=60      (ₓ₆)⇒48ₓ-18y=360                     |48-3y=60
14ₓ+18y=12 (ₓ₁)⇒14ₓ+18y=12                      |     -3y=60-48
                            ------------------⁺                  |        -3y=12
                                       62x=372                 |          y=12/-3 = -4
                                            x=372/62=6       |        b= -4
                                            a=6                    |a+2b= 6+2(-4)
                                                                                =6-8
                                                                                 =-2

kalau mau ada yang ditanyakan tanyakn aja