Bonjour,
a = 3(x - 2) + 5(3 - x)
= 3x - 6 + 15 - 5x
= -2x + 9
b = x(3 + x) - 2(x + 5)
= 3x + x² - 2x - 10
= x² + x - 10
c = -2(x - 7) - 2(x² + x) + 4(x² + 1)
= -2x + 14 - 2x² - 2x + 4x² + 4
= 2x² - 4x + 18
d = 2x(-x + 5) - x²(1 - x)
= -2x² + 10x - x² + x^3
= x^3 - 3x² + 10x
e = -6x(2x² - 3x) - 3(x + 4x²) - x(-3 + 4x)
= -12x^3 + 18x² - 3x - 12x² + 3x - 4x²
= -12x^3 + 2x²
f = 1/2(3/2x + 1/5)
= 3/4 x + 1/10
g = -3/5(2/3x + 4/3)
= - 2/5 x - 4/5
h = 7/5(3/2x² - 3/7)
= 21/10 x² - 3/5
i = -2/5x(3/2x +1/5)
= -3/5 x² - 2/25 x
k = -3/4x²(5/7 - 3/2x)
= -15/28 x² + 9/8 x^3.