Question

imi aleg un numar .adaug la el acelasi numar ,scad din rezultat 30 ,apoi adun 32 si obtin 42.la ce numar m am gandit?

Answer 1

10+10-30+32=

=20-30+32=

=10+32=

=42

Answer 2

Notam nr cu x

[(x+x)-30]+32=42

(2x-30)+32=42

2x-30=42-32

2x-30=10

2x=10+30

2x=40

x=40:2

x=20