Question

Sistemas de equaçao
A) x-y=4
2x-y=9

Answer 1

x-y=4 (I)

2x-y=9 (II)

(I) x=4+y

2(4+y)-y=9

8+2y-y=9

8+y=9

y=9-8

y=1

(I)x-y=4

x-1=4

x=4+1

x=5