Question

resolva os sistemas:

Answer 1

a) x+4y=0
3x+2y=5

x=-4y
3(-4y)+2y=5
-12y+2y=5
-10y=5
y=-5/10
y=-1/2

x=-4.(-1/2)
x=4/2
x=2

(2,-1/2)

b) x+y=14
3x+y=24

y=14-x
3x+14-x=24
2x=24-14
2x=10
x=10/2
x=5

y=14-5
y=9

(5,9)

c) 2x+y=4
3x-3y=8

y=4-2x
3x-3.(4-2x)=8
3x-12+6x=8
9x=8+12
x=20/9

y=4-2.20/9
y=4-40/9
y=36-40
y=-4

(20/9,-4)

d) x+y=60
5x-y=210

6x=270
x=270/6
x=45

45+y=60
y=60-45
y=15

(45,15)