Question

Let x y be a real number. If x * y = x (x-y) then What is the value of 2 * (7 * 1)?​

Answer 1

The value of
`2 *(7 * 1)` is -80

Solution:

Given that x y is a real number

Also given that
`x * y = x(x - y)`

We are asked to find the value of
`2 * (7 * 1)`

To solve it we have to first solve terms in brackets.

`\begin{array}{l}{\text {So, } 7 * 1=7(7-1) \quad[\text {from given rule }]} \\\\ {\rightarrow 7 * 1=7 * 6} \\\\ {\rightarrow 7 * 1=42} \\\\ {\text {Now, the required expression is modified as } 2 * 42} \\\\ {\text {Then, } 2 * 42=2(2-42)=2(-40)=-80} \\\\ {\text {Hence, the value of } 2 *(7 * 1)=-80}\end{array}`