Question 80544
{{{(a^2-a-2)}}}=0 [solve for the a-term by factoring the polynomial]
(a+1)(a-2)=0 [set each factor equal to zero and solve]
a+1=0
a=-1
and
a-2=0
a=2
.
So, the answers are x = -1 and x=2
.
check by plugging the values for x back into the original equation and solve.
{{{(a^2-a-2)}}}=0
Let x=-1
{{{((-1)^2-(-1)-2)}}}=0
1+1-2=0
2-2=0
0=0 [checks out] 
and
{{{(a^2-a-2)}}}=0
Let x=2
{{{((2)^2-(2)-2)}}}=0
4-2-2=0
4-4-0
0=0 [also checks out]
{{{(a^2-a-2)}}}=0