Question

daca a2+8b=20 aflati a+4b
daca 9a+12b+7=28 aflati 3a+4b
daca 4a+10b-3=27 aflati 2a+5b
7a+14b+21=105 aflati 3a+6b
5a+15b+10z=30 aflati 3a+9b+6z
6a-12b-5=67 aflati 13+5a-10b
Cine ma ajuta ii raspund la 10 intrebari + 40 pct din partea mea

Answer 1

a2+8b=20 aflati a+4b2a+8b=20 /:2 => a+4b=10

daca 9a+12b+7=28 aflati 3a+4b
9a+12b=28-7
9a+12b=21 / :3
3a+4b=7

daca 4a+10b-3=27 aflati 2a+5b
4a+10b=27+3
4a+10b=30/:2
2a+5b=15

7a+14b+21=105 aflati 3a+6b
7a+14b=105-21
7a+14b=84/:7
a+2b=12 / x3
3x+6b=36

5a+15b+10z=30 aflati 3a+9b+6z
5a+15b+10z=30/:5
a+3b+2z=6 /x3
3a+9b+6z=18


6a-12b-5=67 aflati 13+5a-10b
6a-12b=67+5
6a-12b=72 /:6
a-2b=12 /x 5
5a-10b=60

Deci 13+60=73