Question

the solution of pair of linear equation 15x+38y=128 and 38x + 15y=243​

Answer 1

Answer:

x=6, y=1

Step-by-step explanation:

The two equations are

     15x + 38y = 128      ... (1)

     38x + 15y = 243      ... (2)

With the aim of eliminating x, scale the equations so that the coefficients of x are the same.  So multiply equation (1) by 38 and equation (2) by 15 to get

     (38)(15)x + 38²y = (38)(128)      ... (3)

     (15)(38)x + 15²y = (15)(243)      ... (4)

Now subtract equation (4) from equation (3) to have an equation with only y:

     (38² - 15²)y = (38)(128) - (15)(243)

=>  1219y = 1219

=>  y = 1

Substituting this into equation (1) now gives

     15x + 38 = 128

=>  15x = 90

=>  x = 6