a + b = 75
a : 3 = b : 2 ==> 2×a = 3×b
Metoda grafica:
a |_____|_____|_____|
b |_____|_____|
5 segmente egale = 75
75 : 5 = 15 (un segment egal)
a = 3 × 15 = 45
b = 2 × 15 = 30
Verificare:
45 + 30 = 75
45 : 3 = 30 : 2
15 = 15 (adevarat)
Metoda algebrica:
a + b = 75 ==> a = 75 - b
2 × (75 - b) = 3 × b
150 - 2×b = 3×b
3×b + 2×b = 150
5×b = 150
b = 150 : 5
b = 30
a = 75 - 30 = 45
Raspuns:
a = 45
b = 30
