Question

Sistema da equação {3x + y = 13
{ x - 2y= 2

Answer 1

{3x+y=13 (x2)

{x-2y=2

6x+2y=26

x-2y=2

7x=28

x=4

x-2y=2

4-2y=2

-2y=2-4

-2y=-2 (x-1)

y=1

Answer 2

y=13-3x
x-2y=2

x-2(13-3x)=2

x=4
y=13-3×4

y=1

(x,y)=(4,1)

3×4+1=13
4-2×1=2

13=13
2=2

x=4
y=1