Question

from linear equations in one variable. divide 36 into two parts in such that a way that 1/5 of one part is equal to 1/7 of the other

Answer 1

$x + y = 36 \\ \frac{x}{5} = \frac{y}{7} \\ 7x = 5y \\ x = \frac{5y}{7} \\ x + y = 36 \\ \frac{5y}{7} + y = 36 \\ \frac{5y + 7y}{7} = 36 \\ 12y = 36 \times 7 \\ y = 3 \times 7 \\ y = 21 \\ x + y = 36 \\ x + 21 = 36 \\ x = 15$