00:01
In this problem, we have been given two sets, a and b, and we need to show that a is a subset of b.
00:06
So let us consider an element x and let x belong to a.
00:11
Now, if x belongs to a, then that will mean that x is 1 or x is 2.
00:17
And this is because the set a contains the elements 1 and 2.
00:21
Now, let us substitute x is equal to 1 in the expression on the left -hand side of the equation in the set b.
00:28
That is x cubed minus 6x squared plus 11 x.
00:32
So 1 cubed minus 6 times 1 squared plus 11 times 1.
00:39
So we end up with 1 minus 6 plus 11 and that is equal to 6.
00:46
So we can see that if we substitute that substitute x is equal to 1 in the expression, we get 6.
00:53
So x is equal to 1 satisfies the equation x cubed minus 6 squared plus 11 x is 7...