Question

Calcule os sistemas abaixos:
{X+Y=14
X/Y=3/4


{X+1/4=Y/8
1/X=1/Y

Answer 1

a) x+y=14
x/y =3/4
4x = 3y
4x-3y=0

x+y= 14 (3)
4X-3y=0

3x+3y= 42
4x-3y=0 (+)
-------------------
7x= 42
x= 42/7
x=6

x+y= 14
6+y=14
y= 14-6
y = 8
B)
x+ 1/4 = y/8
1/x = 1/y
y= x

x + 1/4 = y/8
x + 1/4 = x/8
(8x + 2) /8 = x/8
8x + 2 = x
8x - x = -2
7x = -2
x= -2/7
y= -2/7