If you would like to solve the equation k / 2 + 9 = 30, you can calculate this using the following steps:
k / 2 + 9 = 30
k / 2 = 30 - 9
k / 2 = 21 /*2
k = 21 * 2
k = 42
The result is 42.
- 5/12 + ( - 1/4) =
Adding two negatives results in a negative
-1/4 = -3/12
-3/12 + -5/12 = -8/12
-8/12 + 3/12 < Subtract and take the sign of the BIGGER number.
8 - 3 = 5
- 5/12
Answer: - 5/12
You do 2x20 which is basically 2x2 (4) add a zero and your answer is 40
Correct answer is: distance from D to AB is 6cm
Solution:-
Let us assume E is the altitude drawn from D to AB.
Given that m∠ACB=120° and ABC is isosceles which means
m∠ABC=m∠BAC = 
And AC= BC
Let AC=BC=x
Then from ΔACD , cos(∠ACD) = 
Since DCB is a straight line m∠ACD+m∠ACB =180
m∠ACD = 180-m∠ACB = 60
Hence 

Now let us consider ΔBDE, sin(∠DBE) = 
