Special Operatons in Algebra
Example corresponding to question 5 in algebra_1.
|
Example 1
The operation $\bigotimes$ is defined by $x \bigotimes y = -x^3+4y+2$. If $1 \bigotimes y = - 7$, then $y=$
- $-3$
- $3$
- $-2$
- $4$
- $-5$
Solution
This example is about solving quesions related special operators given their definition.
-
Let us first use the definition of the operation $\bigotimes$ to write the following
$1 \bigotimes y = -(1)^3+4y+2$
Substitute $1 \bigotimes y$ by $-7$ in the equation above to obtain
$-7 = -(1)^3+4y+2$
Simplify the terms in the above equation and solve it
$-7 = -1+4y+2$
$-7 = 1+4y$
$4y = -8$
$y = - 2$
Answer C
|