Question

Resolva:
{A+B= 17
{A-B=-1



{A=-2b
{-A+b=1



{Y=X sobre 3
{X-6y=-3

Answer 1

a) {A+B= 17
{A-B=-1

2A= 16
A= 16/2
A= 8

A+B= 17
8 + B= 17
B= 17 - 8
B= 9

b) {A=-2b
{-A+b=1
-A+b=1
-(-2b) + b= 1
2b + b= 1
3b= 1
b= 1/3

{A=-2b
A= -2 (1/3)
A= -2/3


c) {Y=X sobre 3
{X-6y=-3

X-6y=-3
X - 6(x/3)= -3
X - 6x/3= -3 mmc: 3

3x - 6x= -9
-3x= -9 (×-1)
3x= 9
x= 9/3
x= 3

X-6y=-3
3 -6y= -3
-6y= -3 + 3
-6y= 0 (×-1)
y= -0/6
y= 0