Question

afla termenul necunoscut 3+?=13 4+?=6 123+?=128

Answer 1

$\bold{1)} \ 3+x=13 \\ x=13-3 \\ \boxed{x=10}. \\ \\ \bold{2)} \ 4+y=6 \\ y=6-4 \\ \boxed{y=2}. \\ \\ \bold{3)} \ 123+z=128 \\ z=128-123 \\ \boxed{z=5}.$

Answer 2

a=13-3
a=10
3+10=13
a=6-4
a=2
4+2=6
a=128-123
a=5
123+5=128