Question

4) resolva as sistemas de equaçao pela metolo da adição?a) (2×+3y=8 5×-3y=1. B) ×+2y=7 ×-2y=-5

Answer 1

a) 2x+3y=8
5x-3y=1

7x=9
x=9/7

2 (9/7)+3y=8
18/7+21y=8
21y=8-18/7
21y=56-18
21y=38
y=38/21

b) x+2y=7
x-2y=-5

2x=2
x=2/2
x=1

1+2y=7
2y=7-1
2y=6
y=6/2
y=3