Răspuns :
b = 7a
2a + 3b = 460
2a + 3 * 7a = 460
2a + 21a = 460
23a = 460
a = 460 : 23
a = 20
b = 7 * 20
b = 140
2a + 3b = 460
2a + 3 * 7a = 460
2a + 21a = 460
23a = 460
a = 460 : 23
a = 20
b = 7 * 20
b = 140
2a+3b =460
b =7a
2a + 3*7a =460
2a +21a =460
23a =460
a =20
b =7a
b =7*20 =140
verif ; 2*20+3*140 =40+420 =460
b =7a
2a + 3*7a =460
2a +21a =460
23a =460
a =20
b =7a
b =7*20 =140
verif ; 2*20+3*140 =40+420 =460