Question

Resolva os sistemas
a){2x+y=7
{3x+2y=13
b){3x-y=6
{3x-2y=10

Answer 1

a)

2x+y = 7
y = 7-2x

3x+2y = 13
3x+2(7-2x) = 13
3x+14-4x = 13
14-x= 13
-x= 13-14
-x=-1
x= 1

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

b)

3x-y=6
3x-6=y

3x-2y=10
3x-2(3x-6) = 10
3x-6x +12 = 10
-3x+13 = 10
-3x=10-13
-3x=-3
x=-3/-3
x=1

3x-6=y
3(1)-6=y
3-6=y
-3=y