Answer:
x = - 2
Step-by-step explanation:
As it has been given that 
, 
.
We need to find the value of the following:
(i) 
, substituting the value of 'x' and 'y' in the expression, we get:
So, 
(ii) 
, substituting the value of 'x' and 'y' in the expression, we get:
So, 
(iii) 
, we need to substitute the value of 'x' and 'y' in the expression, for this, we can use distributive property of multiplication that says,
Using the distributive property of multiplication:
Now, we know that 
We get, 
Therefore, =
.
(iv) We have, 
, we need to substitute the value of 'x' and 'y' in the expression, we get:
Again, we can use distributive property of multiplication that says,
So,
since, 
we get,
Therefore,
Answer:
c and d
Step-by-step explanation:
Is this what you wanted?
Step-by-step explanation:
First, say that
x
4
=
u
.
The equation then can be written as
u
2
−
10
u
+
9
=
0
This more likely looks familiar.
This can be factored into
(
u
−
9
)
(
u
−
1
)
=
0
From here it can be said that if the product of two terms is
0
, at least one of the terms must be equal to
0
, so set both terms equal to
0
to find when this is true.
u
−
9
=
0
u
−
1
=
0
Which can be rewritten as
u
=
9
u
=
1
Now, go back to the beginning when we said that
x
4
=
u
. Replace each instance of
u
with
x
4
.
x
4
=
9
x
4
=
1
Solve each.
x
4
=
3
2
x
=
±
(
3
2
)
1
4
x
=
±
(
3
)
1
2
x
=
±
√
3
x
4
=
1
x
=
±
1
When in doubt, check a graph:
graph{x^8-10x^4+9 [-13.64, 14.84, -2.16, 12.08]}
The zeros (solutions) are at
x
=
±
1
,
±
√
3
.
