Question

9+х=12,х+4=12,12-х=6,х-7=5

Answer 1

9+x=12
X=12-9
X=3

X+4=12
X=12-4
X=8

12-x=6
X=12-6
X=6

X-7=5
X=7+5
X=12

Answer 2

9+х=12
х=12-9
х=3
9+3=12

х+4=12
х=12-4
х=8
8+4=12

12-х=6
х=12-6
х=6
12-6=6

х-7=5
х=5+7
х=12
12-7=5