Question

it has to be solved by cross multiplication only plz answer this.on 13 may I have to give exam

Answer 1

Given : ax + by = a - b   ----------- (1)

Given : bx - ay = a + b   ------- (2)

Multiply (1) * a and (2) * b, we get

a^2x + bay = a^2 - ab  ------ (3)

b^2x - bay = ab + b^2  ------ (4)

On solving (3) & (4), we get

a^2x+ bay + b^2x - bay = a^2 - ab + ab + b^2

a^2x + b^2x = a^2 + b^2

x(a^2 + b^2) = a^2 + b^2

x = a^2 + b^2/a^2 + b^2

x = 1.


Now,

Substitute x = 1 in (2), we get

bx - ay = a + b

b - ay = a + b

-ay = a + b - b

-ay = a

y = -a/a 

y = -1

y = -1.


Therefore x = 1 and y = -1.


Hope this helps!