Proof: a) x ^ 2 + x + 1 > 0 for all x; 
b) 2 x ^ 2 + 2 x + 1 > = 0 for all x

Search GTNN
a) x ^ 2-4 x + 1
b) 3 x ^ 2-6 x-1
c) 4 x ^ 2 + 4 x-2
Search GTLN
a) 4 x-x ^ 2-5
b) 5-x ^ 2-6 x

for triangle ABC in A balance. guys that BH is perpendicular to AC. D is the midpoint of BC. On the beam of rays DH took the point M to DM = DH. Proven 
a is, triangle BMD = triangle CHD
b, BC is the ray of ABM corner stool
c, suppose x BH HC.so > comparison of two go cs BHD and CHD

For the triangle loss in A = 90 degrees

M point in BC. drawing-MO perpendicular to AB

MK drawing perpendicular to ac. On the beam of rays of OM and KM in turn retrieved 2 points D and E for OM = OD, KM = KE

C/M AD = AE

phân tích đa thức thành nhâ tử

1,x^3−x^2+x−1

2,6x^2y−2xy^2+3x−y

3,4x^2+1

4,x^2−9x+8

5,x^3−2x^2y+3xy^2

6,x^2−6x+y−y^2

7,x^2−xy−2x+2y

for 3\(a^2+3b^2=10ab\)

because b>a >0

analysis of the factor

1,\(x^3+2x^2+x-2\)

2,\(x^2-2x+5\)

3,\(a^3+4a^2+4a+3\)

4,\(4a^2b^2-\left(a^2-b^2\right)^2\)

5,\(a^3+6a^2+8+12a\)

6,\(4+4x-x^2\)

7,\(\left(2x-5\right)^2-\left(5x-3x\right)\)

Search x know

1,\(x\left(x-3\right)+x-3=0\)

2,\(5x\left(x-2\right)-x+2=0\)

1,analysis of the factor

zx-zy-5x+5y

\(x^2-y+x^2y-x^3\)

\(4x^2-t^2-4ty-4y^2\)

\(4x-x^2-4+y^2\)

\(y^2-x^2-2x-1\)

1, a school has 550 female students. Eagle boys 10/11 of the female student. ask the school which have all how many students?

2, men have 42 volumes. for the average 2/7 of breaks, to left after rupture of 3/5 for peace. ask the average and how much the washhouse you get each term booklet