Question

by what should be subtracted from the product of 2/7 &3/8 to get -3/7?

Answer 1

Answer:

Let us subtract x

Therefore

$\frac{2}{7} \times \frac{3}{8} - x = - \frac{3}{7} \\ \frac{1}{7} \times \frac{3}{4} + \frac{3}{7} = x \\ \frac{1 \times 3}{7 \times 4} + \frac{3}{7} = x \: \\ \frac{3}{28} + \frac{3}{7} = x \\ \frac{3}{28} + \frac{12}{28} = x \\ x = \frac{15}{28}$