21 because 9+10 is actually 21
Answer:
Step-by-step explanation:
BD is opposite the 30° angle. The sine of 30° is 0.5. The sin of an angle in a right triangle is opposite/hypotenuse so BD = sin 30°x8.
Now you have two known lengths The third can be found by applying the Pythagorean theorem: BC²+BD²=CD², from which you can establish a numerical value for BC.
Answer:
1320, permutation
Step-by-step explanation:
There are 12 members
Pick a president
We have 12 choices
Now there are 11 people left to pick from
now pick a vp
We have 11 choices
Now there are 10 people left to pick from
now pick a secretary
We have 10 choices
12*11*10 = 1320
This is a permutation since it matters who is president, vp and secretary
The number is 142
you first make an equation ;
86+x=2x-56
Add 56 to both sides
142+x=2x
Subtract x from both sides
142=x