Question

1.rezolvati ecuatia: testul 2
a)3/5x-1/4=2/5 b)2,5x-1,7=1,5x+11,3

2 suma a trei numere este 3/5. determinati media aritmetica a acestora

testul 3
1.a)3/8=1/4+x b)5/6-x=2/3

2. media aritmetica a numerelor a si b este 10 calculati media aritmetica a numerelor a,b si 10.

Answer 1

Testul 2
1.a)3/5x=2/5+1/4
3/5x=13/20=>65x=60=>x=60/65=12/13
b)2,5x-1,5x=1,7+11,3=>x=13

2.a+b+c=3/5
(a+b+c)/3=3/5:3=>(a+b+c)/3=3/5·1/3=>Media aritm.=1/5

Testul 3
1.a)3/8=1/4+x
3=2+8x=>8x=1=>x=1/8
b)5/6-x=2/3
5-6x=4=>-6x=-1=>x=1/6

2.(a+b)/2=10=>a+b=20
(a+b+10)/3=30/3=10