Solve the following systems of simultaneous linear equations by cross-multiplication method :

3x + 2y = 4

8x + 5y = 9

Solve the following systems of simultaneous linear equations by cross-multiplication method :

3x - 7y + 10 = 0

y - 2x = 3

Solve the following system of simultaneous linear equations by cross-multiplication method :

x + 3y + 4 = 0

3x - y = -2

Solve the following pairs of linear equations by cross-multiplication method:

x - y = a + b

ax + by = a² - b²