Respostas

2014-06-06T23:21:18-03:00
B/4- c/2=0    *(2)
b+c = 90

b/2- c=0
b+c=90
b/2=90
b=2*90
b=180

Substituindo b em  b+c=90
180+c = 90
c=90-180
c=-90
2014-06-06T23:28:13-03:00
 \frac{b}{4} =  \frac{c}{2}  \\ 2b=4c

Então:
 \left \{ {{2b=4c} \atop {b+c=90}} \right.

Isolando b:
b = 90-c

Aplicando b:
2(90-c)=4c \\ 180-2c=4c \\ 180=6c \\  \frac{180}{6} = c  \\ c=30

Aplicando c:
2b = 4(30) \\ 2b = 120 \\ b= \frac{120}{2}  \\ b=60

b = 60
c = 30