Sagot :
Bonjour,
Ex. 2 :
a=5
2a + 5a = 2(5) + 5(5) = 10 + 25 = 35
7a = 7(5) = 35
donc 2a + 5a = 7a
2a + 5 = 2(5) + 5 = 15
2 + 5a = 2 + 5(5) = 27
7a² = 7(5²) = 175
2a² + 5a² = 2(5²) + 5(5²) = 50 + 125 = 175
donc 7a² = 2a² + 5a²
Ex. 3 :
1) 5a³
2) 10a
3) 8a+2
4) 12x
5) 7a+8
6) a²+3a+4