B. -25
The answer to X has to be negative. Since -2/5 is negative and we’re trying to get to 10, we need another negative to cancel out the negative into a positive. Multiply -2/5 by X (-25) so it’s -2/5 x -25/1. Negative times negative is positive. 2 x 25 is 50. 5 x 1 is 5. 50/5 is 10.
