Question

1) calcular

a){y=x-1
{y=-2x+7

b){y=-2x+5
{y=x-1

Answer 1

Olá

a)
-x+y = -1
-x+y = -1

-x = -y-1
-x = -y-1

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

y = -2x+7

y = -2(y+1)+7
y = -2y+5

y- -2y = 5
3y = 5

3y/3 = 5/3
y = 5/3

x = y+1
x = 1+5/3

x = 8/3

R: x = 8/3
y = 5/3

b)
y = -2x+5

- -1•2x+y = 5
2x+y = 5

2x = -y+5
2x = -y+5

2x/2 = 1/2(-y+5)
x = -y/2+5/2

y = x-1

y = -y/2+5/2-1
y = -y/2+3/2

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

3/2y/3/2 = 1
y = 1

x = -y/2+5/2
x = -1/2+5/2
x = 2

R: x = 2
y = 1

Espero ter ajudado!!!