Question

numerele a si b sunt invers proportionale cu 0,25 si 0,2. Determina numerele a si b stiind ca 3a+2b-6 = 60

Answer 1

0,25=25/100=1/4
0,2=2/10=1/5
{a,b}ip{1/4, 1/5}
a/4=b/5=k
a=4k
b=5k
3a+2b-6=60
3a+2b=60+6
3a+2b=66
3·4k+2·5k=66
12k+10k=66
22k=66
k=66/22
k=3
a=4k=4·3=12
a=12
b=5k=5·3=15
b = 15