Question

responda as equações :
×+30=40
30-20+2×=10
3×-10+13=2+28
20×-30=40+30-20

Answer 1

1° X+30=40
     X=40-30= 10
2° 30-20+2×=10
     10+2x=10
         2x=10-10
         2x=0
         X=-2
3°3×-10+13=2+28
    3x-3=30
 3x=30+3
 x=33/3
X=11
4°20×-30=40+30-20
20x=40+30-20+30
20x=80
x=80/20
x=4