Question

Resolva os sistemas:

a) x+y = 10
y=4

b) x+ y= 10
2x- y = 2

c) 2x+y= 7
x- 3y = 16

d) 20x+10y =10
x+y=2

e) 5x - 10y= 15 *(-2)
2x - 4y= 6* (5)

f) 2x+ 3y= 10*(-4)
4x+ 6y= 30*(2)

Answer 1

A) X+4=10 -> X=10-4 -> X=6 E Y= 4

B) X+Y=10 -> X= 10-Y
2(10-Y) - Y =2
20-2Y=2 -> -2Y= 2-20 -> -2Y= -18 (-1) -> 2Y=18 -> Y= 18/2 -> Y=9
X+9=10 -> X=10-9 -> X=1

C) x=16+3y
2(16+3y)+y=7 -> 32+6y=7 -> 6y=7-32 -> 6y=25 -> y=25/6
x-3(25/6)=16 -> x-(25/2)=16 -> x=16+(25/2) -> x= 57/2

D)x=2-y
20(2-y)+10y=10 -> 40-20y+10y=10 -> -10y=-30 -> y=30/10 -> y=-3
x-3=2 -> x=2+3 -> x=5