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.
Answer:
-5/7
Step-by-step explanation:
When you divide fractions, you flip the second fraction, then multiply.
So it becomes -25/28 x 4/5.
This equals -100/140 which reduces to -5/7.
Answer:
Peter's number is 36.
Step-by-step explanation:
If you subtratct 13 from 36, you get 23.
If you multiply that times -3, you get -69.
(The way I got 23 was by dividing -69 and -3)
I hope this helped you even though it's late.
The answer is eight over fifteen ( 8/15)
