Question

Find the value of x in this equation: $\dfrac{{392}}{x} = - 196$
A.2
B.4
C.-2
D.-4

Answer 1

Hint: Use cross multiplication. It’s a problem solving method in which if we have $\dfrac{a}{b} = \dfrac{c}{d}$ , then it can also be written as $ad = bc$.

We have given the equation, $\dfrac{{392}}{x} = - 196$. Using cross multiplication method in the given equation, we get, $\dfrac{{392}}{x} = - 196 \Rightarrow \dfrac{{392}}{{ - 196}} = x \Rightarrow - 2 = x$. Hence the required value of x is -2.

Note: Cross multiplication method is essentially division. We divide according to our convenience. Here, we needed to find the value of x, so we took it to the right hand side and both numbers to the same side of the equation using the cross multiplication method.