I think it would be -9.64
Answer:
C
Step-by-step explanation:
Just use elimination strategy
The commutative property of addition means that when you see a problem, you change the order. The co in commutative means change order. That's what my teacher told me.
First, we expand the equation:

Then, we combine certain terms in order to simplify them using trigonometry identities.

Note these identities:
Pythagoran relation:

Sum and Difference Formula/Identities:

Thus, if we apply these identities, the simplified equation would be:

Simplying further, the answer would be
Answer:
x = 31
Step-by-step explanation:
Given:
MN = 20
PQ = x
RS = 42
Required:
Value of x
SOLUTION:
In a trapezoid, the midsegment length equals the sum of both bases divided by 2
This implies that:
PQ = ½(MN + RS)
Plug in the values
x = ½(20 + 42)
x = ½(62)
x = 31