X representa o numero das suas respostas certas.
y represnta o numero das suas respostas erradas.
O total de perguntas <span>é 25, portanto
x + y = 25
Agora tratamos do dinheiro.
Come</span>ça com <span>R$ 500,00
Pelas x respostas certas, recebe 200x.
Pelas y respostas errads perde 150y.
O total de dineheiro inicial mais os ganhos menos as perdas s</span>ão iguais a
R$ 600,00, portanto
500 + 200x - 150y = 600
200x - 150y = 100
20x - 15y = 10
Temos um sistema de duas equações com duas variaveis.
<span>x + y = 25</span>
20x - 15y = 10
15x + 15y = 375
+ 20x - 15y = 10
---------------------------
35x = 385
x = 11
x + y = 25
11 + y = 25
y = 14
Resposta: Errou 14 perguntas.
Each straw is 4-1/8 inches long.
You have one gigantic piece of straw material, 123-3/4 inches long.
How many straws can you cut it up to make ?
===> (123-3/4) divided by (4-1/8) straws.
Each one costs $0.015 to make.
So, once you find the number of short straws you have,
multiply
===> (the number of short straws) x ($0.015) .
That'll tell you how much it costs to make all of them.
Now you know how to do it on your own.
If you don't get 30 straws and $0.45 , please try again.
7. increasing; non-linear
8.A. y=4^x
9.A. y=6x
Hello!
Answer: (c) An irrational number
Good luck! :)
