a/b=4/5 ; b/c=5/3 ; a+b+c=120 a=? b=? c=?

Răspuns:

Explicație pas:

Putem scoate totul in functie de a

a / b = 4 / 5 => 5a = 4b => b = 5 / 4 *  a

b / c = 5 / 3 => b = 5 / 3 c, inlocuim

5 / 4 * a = 5 / 3 c => c = 3 / 4 a

a + b + c = 120

5 / 4 * a + 3 / 4 * a + a = 120

5a + 3a + 4a = 480(am adus la acelasi numitor)

12a = 480 => a = 40

b = 5 / 4 * a = 50

c =  3 / 4 * a = 30

a = 40 , b = 50 , c = 30

a/b=4/5=>a=4b/5

b/c=5/3=>c=3b/5

a+b+c=120

4b/5+b+3b/5=120

4b/5+/5b/5+3b/5=120

12b/5=120

12b=5*120

12b=600

b=50

a=4*50/5=40

c=3*50/5=30