Question

precizeaza daca ecuațiile sunt echivalente​

Answer 1

Răspuns:

3. a) -x+21=7, x=14

-14+21=7

7=7 (A)

b) 11-x=2, x=9

11-9=2

20=2 (A)

c) 3x-35=1, x=-12

3·(-12)-35=1

-36-35=1

-71=1 (F)

d) x:2=9, x=18

18:2=9

9=9 (A)

e) -16:x=-2, x=-8

-16:(-8)=-2

2=-2 (F)