Question

Solve the pair of linear equation 21x+47y=110. 47x+21y=162

Answer 1

Let 21x + 47y = 110 be Equation 1 i.e (1),
and 47x + 21y = 162 be Equation 2 i.e (2),

Now subtract (1) and (2),

=> -26x + 26y = -52,
=> Divide both sides with -26,
=> x - y = 2, Add y on both sides,
=> x = 2 + y, Now substitue this value in any of the equations,

I am going to substitue x = y+2 in 1st equation,

=> 21(y+2) + 47y = 110, Simplifying the left side,
=> 21y + 42 + 47y = 110,
=> 68y = 110 -42,
=> 68y = 68,
=> y = 1,

We know that, x = y+2,
=> x = 1+2 = 3,

Therefore the value of x is 3 and y is 1, We can also do this problem by multiplying Equation 1 with 47 and equation 2 with 21 and subtracting it,

But this is the shortest method I did ! So therefore the value of x is 3 and y is 1,

Hope you understand, Have a Great Day, Merry Christmas !
Thanking you, Bunti 360 !