M+4n=8
m=n-2
we see that m=n-2
so we can subsitute 'n-2' for m in the first equation
(n-2)+4n=8
n-2+4n=8
5n-2=8
add 2 to both sides
5n=10
divide by 5
n=2
subsitute
n=2
m=n-2
m=2-2
m=0
m=0
n=2
the answer is c. 0,2
Answer:
probability that he or she will answer at least 4 problems correctly = 0.5
Step-by-step explanation:
probability that he or she will answer at least 4 problems correctly is given as;
P (at least 4 correctly) = P (exactly 4 correctly) + P (all 5 correctly)
Since there are 10 problems. 4 is from the 7 problems chosen and 1 is from the 3 problems we can't figure out. Thus, P(exactly 4 correctly) = 7C4 x 3C1
Thus, P (at least 4 correctly) = [ (7C4) x (3C1) ] / (10C5)] + [(7C5)/(10C5)]
= [(35 x3)/252 ] + [21/252]
= [ 105/252 ] + [ 21/252 ]
= 126 / 252
= 0.5
The pattern is mutiplying each time by 3 so the 6th figure would be 18 because 3×6=18
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.
