What is the answer to C??
1 answer:
Answer:
x = 1
Step-by-step explanation:
3^2x - 9 (3^-2x) = 8
<=> 3^2x - 9/(3^2x) = 8
Given that 3^2x = y [1] (y>0), we have a new equation as follows:
y - 9× = 8
<=> y - 9/y = 8
<=> y(y - 9/y) = y×8
<=> y^2 - 9 = 8×y
<=> y^2 - 8y - 9 = 0
<=> (y^2 + y) - (9×y + 9) = 0
<=> y(y + 1) - 9(y + 1) = 0
<=> (y - 9)(y + 1) = 0
=> y = 9, or y = - 1
However, as 3^2x > 0, y>0.
Therefore, y = 9.
Replace y with 9 in [1], we have:
3^2x = 9 = 3^2
=> 2x = 2
=> x = 1
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Answer:
Angle BCD is 13 degrees
Step-by-step explanation:
Here, we want to find the measure of angle BCD
To get this, we need an appropriate diagram. The diagram can be seen in the attachment.
To find the value of BCD, we can use an important triangle theorem.
This is that the sum of opposite interior angles of a triangle equals the exterior angle.
Thus, we have that;
BCD + DBC = CDE
hence;
3x + 5 + 2x + 3 = 9x-12
5x + 8 = 9x -12
9x-5x = 8 + 12
4x = 20
x = 20/4
x = 5
So the measure of BCD will be 2(5) + 3 = 10 + 3 = 13
