যদি 5xy + 28x - 2 = 0 এবং y = -4 হয়, তাহলে 4x + y = কত?

A 3

B 4

C -3

D 6

Correct Answer: Option C

5xy+28x-2 = 0

বা, 5x(-4)+28x - 2 = 0

বা, -20x+28x-2 = 0

বা, 8x = 2 বা, \(x = \frac{2}{8} = \frac{1}{4}\) বা, \(4x + y = 4.\frac{1}{4} + ( - 4) = 1 - 4 = - 3\)