Bonjour
1)
(7 + x) (y + 3) = 7 * y + 7 * 3 + x * y + x * 3 = 7y + 21 + xy + 3x
2)
a. (2 + x) (5 + y) = 10 + 2y + 5x + xy
b. (y + 8) (x + 10) = xy + 10y + 8x + 80
c. (x + 8) (1,5 + x) = 1,5x + x² + 12 + 8x
d. (y + 6) (y +9) = y² + 9y + 6y + 54 = y² + 15y + 54.
