Wiskunde.net

20.
a. 12 = 2 ⋅ 2 ⋅ 3
b. 18 = 2 ⋅ 3 ⋅ 3
c. 28 = 2 ⋅ 2 ⋅ 7
d. 60 = 2 ⋅ 2 ⋅ 3 ⋅ 5
e. 80 = 2 ⋅ 2 ⋅ 2 ⋅ 2 ⋅ 5
f. 90 = 2 ⋅ 3 ⋅ 3 ⋅ 5

21.
a. 12pq = 2 ⋅ 2 ⋅ 3 ⋅ p ⋅ q
b. 20pq² = 2 ⋅ 2 ⋅ 5 ⋅ p ⋅ q ⋅ q
c. 11xy² = 11 ⋅ x ⋅ y ⋅ y
d. 25x²y = 5 ⋅ 5 ⋅ x ⋅ x ⋅ y
e. 24x³y² = 2 ⋅ 2 ⋅ 2 ⋅ 3 ⋅ x ⋅ x ⋅ x ⋅ y ⋅ y
f. 21x²yz³ = 3 ⋅ 7 ⋅ x ⋅ x ⋅ y ⋅ z ⋅ z ⋅ z

22.
a. x² - 5x
b. 3x + 33
c. 3a² - 2ab
d. 15a² + 3a
e. x³ - 8x²
f. -2x² + 14x

23.
a. b(8a + 9)
b. x(2x + 1)
c. a(3b + 1)
d. x(5x - 3)

24.
a. 2(2x + 3y)
b. x(4 - y)
c. x(x + 18)
d. 2(p - 3)
e. p(q + r)
f. x(x - 5)
g. x(3x + 5)
h. x(7y - 20)
i. b(8a - 3)

25.
a. b(a - 6c)
b. a(a + 1)
c. b(a² - 3)
d. x(7 - yz)
e. 4(3p - 2q)
f. 9(2x² + yz)

26.
a. p(6q - 30)
b. 6(pq - 5p)
c. 2p(3q - 15)
d. 6p(q - 5)

27.
a. 3a(b + 3)
b. 3b(4a - 3)
c. 3a(a + 2)
d. 3(a² - 2b)
e. 3a(b - 1)
f. 3a(b - 3c)
g. 4xy(3z - 4)
h. 2x(y + 4z)
i. 5x²(1 - 3x)

28.
a. 6x(x² - 2)
b. 5x(5x - 6)
c. 5x²(2 + y)
d. 3x²(2x² - 1)
e. 6abc(3a + 2b)
f. x²(x² - x + 1)
g. x(4x + y - y²)
h. 2x⁵(6x³ + 9x - 8)
i. 3pq²r(3p² - 2r²)

29.
a. 7 x 11 x 13 = 1001