[ 7×( 5a+2 ) +3 × ( 5a + 2 ) ]: 12=10​

Răspuns :

Răspuns:

7*(5a+2)+3*(5a+2)=120

(5a+2)(7+3)=120

(5a+2)*10=120

5a+2=12

5a=10

a=2