Answer:
1.8
Step-by-step explanation:
Solve for x
90
x
=
81
+
25
x
2
Subtract
25
x
2
from both sides of the equation.
90
x
−
25
x
2
=
81
Subtract
81
from both sides of the equation.
90
x
−
25
x
2
−
81
=
0
Factor the left side of the equation.
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−
(
5
x
−
9
)
2
=
0
Multiply each term in
−
(
5
x
−
9
)
2
=
0
by
−
1
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(
5
x
−
9
)
2
=
0
Set the
5
x
−
9
equal to
0
.
5
x
−
9
=
0
Solve for
x
.
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x
=
9
5
The result can be shown in multiple forms.
Exact Form:
x
=
9
5
Decimal Form:
x
=
1.8
Mixed Number Form:
x
=
1
4
5
Upgrade to
Answer:
A, C
Step-by-step explanation:
Actually, those questions require us to develop those equations to derive into trigonometrical equations so that we can unveil them or not. Doing it only two alternatives, the other ones will not result in Trigonometrical Identities.
Examining
A) True

Double angle 
B) False,
No further development towards a Trig Identity
C) True
Double Angle Sine Formula 

D) False No further development towards a Trig Identity
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