Question 73

If $$a * b = a + b + ab$$ for $$a, b \epsilon Q$$ then the value of $$x$$ satisfying $$(1 * 2) * x = -13$$ is

Solution

Given,  $$a * b = a + b + ab$$  and

$$(1 * 2) * x = -13$$

$$\Rightarrow$$ $$(1 + 2 + 1.2) * x = -13$$

$$\Rightarrow$$ $$5 * x = -13$$

$$\Rightarrow$$ $$5 + x + 5x= -13$$

$$\Rightarrow$$ $$5 + 6x = -13$$

$$\Rightarrow$$ $$6x = -18$$

$$\Rightarrow$$ $$x = -3$$

Hence, the correct answer is Option B


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