Pour toutes les valeurs entières de x de 4 à 9, calculer : a) 6 X (x+3)     b) 5 X x + 4     c) x X x + 6

* signifie multiplié par
a) 6(x+3)
x = 4 ; 6(4+3) = 6*7 = 42
x = 5 ; 6(5+3) = 6*8 = 48
x = 6 ; 6(6+3) = 6*9 = 54
x = 7 ; 6(7+3) = 6*10 = 60
x = 8 ; 6(8+3) = 6*11 = 66
x = 9 ; 6(9+3) = 6*12 = 72

b)5x+4
x = 4 ; 5*4+4 = 20+4 = 24
x = 5 ; 5*5+4 = 25+4 = 29
x = 6 ; 5*6+4 = 30+4 = 34
x = 7 ; 5*7+4 = 35+4 = 39
x = 8 ; 5*8+4 = 40+4 = 44
x = 9 ; 5*9+4 = 45+4 = 49

c) x*x+6
x = 4 ; 4*4+6 = 16+6 = 22
x = 5 ; 5*5+6 = 25+6 = 31
x = 6 ; 6*6+6 = 36+6 = 42
x = 7 ; 7*7+6 = 49+6 = 55
x = 8 ; 8*8+6 = 64+6 = 70
x = 9 ; 9*9+6 = 81+6 = 87