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    can you explain me how 20/19 and 45/19 have got
    Davneet Singh's image
    Davneet Singh

    Hello

    (20/19, 45/19) is the intersection point of both lines

     

    For lines

    3x + 5y = 15               ...(1)

    5x + 2y = 10               ...(2)

     

    For equation (1)

    3x + 5y = 15

    3x = 15 - 5y

    x = (15 - 5y)/3

     

    Putting value of x in (2)

    5x + 2y = 10

    5 × (15 - 5y)/3 + 2y = 10

    Multiplying by 3 both sides

    3 × 5 × (15 - 5y)/3 + 3 × 2y = 3 × 10

    5(15 - 5y) + 6y = 30

    5(15) - 5(5y) + 6y = 30

    75 - 25y + 6y = 30

    75 - 19y = 30

     75 - 30 = 19y

    45 = 19y

    19y = 45

    y = 15/19 

     

    Now, putting y = 15/19 in (1)

    3x + 5y = 15

    3x + 5(15/19) = 15

    3x + 75/19 = 15

    3x = 15 - 75/19

    3x = (15 × 9 - 75)/19

    3x = (135 - 75)/19

    3x = 60/19

    x = 60/(19 x 3)

    x = 20/19

     

    So, point is (20/19, 45/19)


    Written on Oct. 17, 2017, 10:20 p.m.