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) = 

Answer:
1) 2/7
2) 8/11
3) 3/2 or 1 1/2
4) 32/35
Step-by-step explanation:
1.5/7•14/35
= 5/7 × 14/35
Using Cancellation method
= 1/1 × 2/7
= 2/7
2.[4/5][10/11]
= 4/5 × 10/11
Using Cancellation method
= 4/1 × 2/11
= 8/11
3.8 3/4 multiplied by 2/9
= 8 3/4 × 2/9
= 27/4 × 2/9
= 3/2 × 1/1
= 3/2
= 1 1/2
4. [4/5]10/11][7/8]
40/50 ÷ 77/88
= 40/50 × 88/77
= 40/50 × 8/7
= 40/25 × 4/7
= 8/5 × 4/7
= 32/35
We use the trinomial theorem to answer this question. Suppose we have a trinomial (a + b + c)ⁿ, we can determine any term to be:
[n!/(n-m)!(m-k)!k!] a^(n-m) b^(m-k) c^k
In this problem, the variables are: x=a, y=b and z=c. We already know the exponents of the variables. So, we equate this with the form of the trinomial theorem.
n - m = 2
m - k = 5
k = 10
Since we know k, we can determine m. Once we know m, we can determine n. Then, we can finally solve for the coefficient.
m - 10 = 5
m = 15
n - 15 = 2
n = 17
Therefore, the coefficient is equal to:
Coefficient = n!/(n-m)!(m-k)!k! = 17!/(17-5)!(15-10)!10! = 408,408
You have to get y by itself. Divide by 7 on both sides to get 1.43x-11=y. Hope this helps! ;)