Question

solve X upon a + y upon B is equals to 2 and a x minus b y is equals to a square minus b square​

Answer 1

Answer:

By cross multiplication, do you mean cross multiplication of the coefficients of the variables?

xa+yb=2

ax−by=a2−b2

Rewrite the first equation in a more beautiful form. Multiply it throughout by ab .

bx+ay=2ab

The coefficients of the variables are interchanged between the two equations. I assume that by cross multiplication, you mean making the coefficients equal, so that a simple subtraction of the equations will eliminate a variable.

Multiply the first equation by a and the second by b .

abx+a2y=2a2b

abx−b2y=a2b−b3

Subtract them.

(a2+b2)y=(a2+b2)b

⟹y=b

Substituting this value in any of the above equations will yield the value of x .

bx+ay=2ab

⟹bx+ab=2ab

⟹x=a