Question

2v+250=4a+100
3v+6a=975

Answer 1

2v+250=4a+100  ==> 2v+250-4a-100 = 0 ===> 2v-4a+150 =0
3v+6a=975

remontando

2v-4a+150 = 0  (3)
3v+6a-975 = 0  (-2)

 6v-12a+450 = 0
-6v-12a+1950 = 0
somando
0v-24a+2400=0
24a = -2400
a = -2400/24
a = -100

substituindo
2v-4a+150 = 0

2v-4(-100)+150 = 0
2v+400+150 = 0
2v +550 = 0
2v = -550
v =-550/2
v=-275

comprovando
2v-4a=-150

2(-275)-4(-100)= -150975
-550+400 = -150
-150 = -150