Question

Resolva os sistemas

B) 2x-5y=0
7x-6y=46
C) x+y=-1
2x+3y=0
D) y=2x-1
y=-3x+29
E) x+6y=1
2x-7y=40

DESDE DE JÁ OBRIGADO

Answer 1

Você precisa primeiro isolar um do termos:

B) |2x-5y=0
|7x-6y=46← vamos usar esse aqui primeiro

7x-6y=46
7x=46+6y
x= (46+6y)/7

2x-5y=0
2•(46+6y)/7-5y=0
92+12y/7-5y=0
12y-5y= 92•7
7y=92•7
y=92

2x-5•92=0
2x-460=0
x=460/2
x=230

C) |x+y=-1
|2x+3y=0← primeiro

2x+3y=0
2x=-3y
x=-3y/2

|x+y=-1
-3y+y=-1
2y=-1
y=-1/2

|x+y=-1
x+(-1/2)=-1
x-1/2=-1
x=-1+1/2
x=-1/2

D) |y=2x-1
|y=-3x+29←

y=-3x+29
-3x+y=29
-3x=29-y. (-1)
3x=y-29
x=y-29/3

|y=2x-1
y=2•(y-29/3)-1
y=2y-58-1
y-2y=-59
-y=-59 (-1)
y=59

y=2x-1
59=2x-1
2x=59+1
2x=60
x=60/2
x=30

E) x+6y=1
2x-7y=40←

2x-7y=40
2x=40+7y
x=40+7y/2
x=20+7y/2

|x+6y=1
20+7y/2+6y=1
7y/2+12y/2=1-20
7y+12y/2=-19
19y=-19
y=-19/19
y=1

|x+6y=1
x+6•1=1
x=1-6
x=-5