Use the method of elimination to find the solution of the following pair of linear equations: $0.4 x + 0.3 y = 1.7, 0.7 x - 0.2 y = 0.8$

Solve the following pair of linear equations by the method of substitution: $8x - 3y = 1$ and $34x - 3y = 14$.

The length of a rectangle is five less than thrice its breadth. The perimeter of a rectangle is $110$. If we take $l$ as length and $b$ as breadth,then which of the following equations represents the relationship between length and breadth?

If the sum and the product of the digits of a two-digit number are the same,then the number is $\ldots \ldots \ldots \ldots$

Solve the following pair of equations: $(a \neq 0, b \neq 0)$
$\frac{2}{a} + \frac{3}{b} = 1$
$\frac{1}{a} + \frac{1}{b} = 1$

The numerator of a fraction is $4$ less than the denominator. If the numerator is decreased by $2$ and the denominator is increased by $1,$ then the denominator becomes eight times the numerator. Find the fraction.