👤
a fost răspuns

6)Daca a*b=30si a*c=18, calculati a(b+c):16 si a(b-c):4.

Răspuns :

a=30/b
a=18/c
30/b=18/c
30c=18b
10c=6b
5c=3b
c=3b/5
30(b+3b/5):16=(30b+90b/5):16=(30b+18b):16=48b:16
b=48:16
b=3
a=10

(30/b*b-30/b*3b/5):4=(30 - 90/5):4=(30-18):4=12:4=3