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Svetradugi [14.3K]
4 years ago
11

Quando existe, dizemos que a solução de um sistema de equações lineares é o conjunto ordenado de números que satisfaz todas as e

quações que o compõe. Você foi sorteado para participar de um show de prêmios em um programa de televisão da sua cidade. A regra do jogo é a seguinte: para cada resposta certa, você ganha R$ 200,00; para cada resposta errada, perde R$ 150,00. No início do jogo, você recebeu R$ 500,00 em créditos. Se você respondeu todas as 25 perguntas e terminou o jogo com R$ 600,00, quantas perguntas errou?
Mathematics
1 answer:
QveST [7]4 years ago
5 0
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.


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    left:  factor of 3*-8                             right:  factor of 3*-8

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