Question

solve the following equation by cross multiplication method 7x+ 3y =4. 2x+ 5y= 1​

Answer 1

Answer:

29.4x² + 35xy + 12.6xy + 15y² = 1

Cross multiplication method

Example problem:

$\frac{x}{y}=\frac{a}{b} \\\\bx = ay$

Here,

$7x+ 3y = 4. 2x+ 5y = 1\\\\7x+ 3y =\frac{1}{4. 2x+ 5y} \\\\Using \ cross\ multiplication\ method\\\\(7x+ 3y)(4. 2x+ 5y) =1\\\\7x(4. 2x+ 5y) + 3y(4. 2x+ 5y) = 1\\\\29.4x^{2} +35xy+12.6xy+15y^{2} = 1$