Question

Đã trả lời bởi chuyên gia

Answer 1

a.

$3 x^{2} - 5 x - 2 = 3 x^{2} - 6 x + x - 2 = 3 x (x - 2) + (x - 2) = (x - 2) (3 x + 1)$

b.

$2 x^{2} + x - 6 = 2 x^{2} + 4 x - 3 x - 6 = 2 x (x + 2) - 3 (x + 2) = (x + 2) (2 x - 3)$

c.

$15 x^{2} + 7 x - 2 = 15 x^{2} - 3 x + 10 x - 2 = 3 x (5 x - 1) + 2 (5 x - 1) = (5 x - 1) (3 x + 2)$

d.

$a^{2} - 5 a - 14 = a^{2} + 2 a - 7 a - 14 = (a^{2} + 2 a) - (7 a + 14) = a (a + 2) - 7 (a + 2) = (a + 2) (a - 7)$

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Answer 2

a.

$3 x^{2} - 5 x - 2 = 3 x^{2} - 6 x + x - 2 = 3 x (x - 2) + (x - 2) = (x - 2) (3 x + 1)$

b.

$2 x^{2} + x - 6 = 2 x^{2} + 4 x - 3 x - 6 = 2 x (x + 2) - 3 (x + 2) = (x + 2) (2 x - 3)$

c.

$15 x^{2} + 7 x - 2 = 15 x^{2} - 3 x + 10 x - 2 = 3 x (5 x - 1) + 2 (5 x - 1) = (5 x - 1) (3 x + 2)$

d.

$a^{2} - 5 a - 14 = a^{2} + 2 a - 7 a - 14 = (a^{2} + 2 a) - (7 a + 14) = a (a + 2) - 7 (a + 2) = (a + 2) (a - 7)$

Answer 3

a/ 3x2−5x−23x2−5x−2

=3x2−3x−2x−2=3x2−3x−2x−2

=3x(x−1)+2(x−1)=3x(x−1)+2(x−1)

=(x−1)(3x+2)=(x−1)(3x+2)

b/ 2x2+x−62x2+x−6

=2x2+4x−3x−6=2x2+4x−3x−6

=2x(x+2)+3(x+2)=2x(x+2)+3(x+2)

=(x+2)(2x+3)=(x+2)(2x+3)

c/ 7x2+50x+77x2+50x+7

=7x2+49x+x+7=7x2+49x+x+7

=7x(x+7)+(x+7)=7x(x+7)+(x+7)

=(x+7)(7x+1)=(x+7)(7x+1)

d/ 12x2+7x−1212x2+7x−12

=12x2−9x+16x−12=12x2−9x+16x−12

=3x(4x−3)+4(4x−3)=3x(4x−3)+4(4x−3)

=(4x−3)(3x+4)=(4x−3)(3x+4)

e/ 15x2+7x−215x2+7x−2

=15x2+10x−3x−2=15x2+10x−3x−2

=5x(3x+2)−(3x+2)=5x(3x+2)−(3x+2)

=(3x+2)(5x−1)=(3x+2)(5x−1)

f/ a2−5a−14a2−5a−14

=a2+2a−7a−14=a2+2a−7a−14

=a(a+2)−7(a+2)=a(a+2)−7(a+2)

=(a+2)(a−7)=(a+2)(a−7)

g/ 2m2+10m+82m2+10m+8

=2m2+2m+8m+8=2m2+2m+8m+8

=2m(m+1)+8(m+1)=2m(m+1)+8(m+1)

=(m+1)(2m+8)=(m+1)(2m+8)

h/ 4p2−36p+564p2−36p+56

=4p2−28p−8p+56=4p2−28p−8p+56

=4p(p−7)−8(p−7)=4p(p−7)−8(p−7)

=(p−7)(4p−8)