The larger of two supplementary angles exceeds the smaller by 18 degrees. Find them.

 3. Form the pair of linear equations for the following problems and find their solution by substitution    method.

(ii) The larger of two supplementary angles exceeds the smaller by 18 degrees. Find them.

Solution:      

  Supplementary angle total =180°

       Let be one angle = x

       Let be another angle = y

    We know two supplementary angles total = 180°

          x+y=180°------(1)

     larger angle is exceeds 18° more than smaller angle

          x=y+18----------(2)

     substitute equation (2) in equation (1)

          x+y=180

          y+18+y=180

          2y=180-18=162

          Y=162/2

          Y=81°

     substitute y=81° in equation (2)

          x=y+18

          x=81+18=99

          x=99

       one angle=99°

       another angle=81°