Answer:
1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Step-by-step explanation:
The order in which the teachers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
1 from a set of 2(Either Mrs. Vera or Mr. Jan).
3 from a set of 18 - 2 = 16. So

1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Esta é a trigonometria . Se você desenhar uma linha a partir do topo da casa de luz para o barco, você terá a hypotonuse de um triângulo. Um truque é lembrar que este é um triângulo especial. É um triângulo 30-60-90 , que tem propriedades especiais mostradas na fixação abaixo . por isso sabemos que o lado adjacente que não é o hyposonuse é x√3 . Agora sabemos que x<span>√3 = 20
Solve for x.
x</span><span>√3=20
divide both sides by </span><span>√3.
x=20/(</span><span><span>√3)
</span>Try not to have square roots (</span><span><span>√)</span> in denomenator so multiply top and bottom by </span><span>√3 and get
x=(20</span><span>√3)/3
x is what we are looking for so the answer is </span>
20<span>√3 m </span><span>ou cerca de 34.64 m</span>
Answer:
Step-by-step explanation:
first multiply 1 with 2+5i then multiply 2i with 2+5i and you will get
2+5i+4i+10i^2
then in the next step add 4i and 5i you will get 9i
in the next step put i^2=-1 and you will get -10
in the last step just substract 2-10 you will get -8 and 9i
and your answer will be -8+9i
3
Going up 7 and then down 4 can be represented by 7-4=3