a, `(8x^3-4x^2): 4x -(4x^2-5x) : 2x + (2x)^2`

`=4x (2x^2-x) : 4x - 2x(2x-5/2 ) :2x + 4x^2`

`=2x^2-x-2x+5/2+4x^2`

`=6x^2-3x+5/2`

b, `(3x^3-x^2y) :x^2 -(xy^2+x^2y) :xy + 2x(x+1)`

`=x^2 (3x-y) :x^2 -xy(y+x) + (2x^2+2x)`

`=3x-y-y-x+2x^2+2x`

`=2x^2+4x-2y`

viết đề lại ko hiểu

Tách các phân số ra giùm cho nhờ cái

Đọc loạn cả r

Bây h đăng câu hỏi khác đi

Kiểu vt tách ra á

a)15/16:3/8x3/4

=15/16:6/16x12/16

=15/16x16/6x12/16

=15/6x12/16

=30/16=15/8

b)5/11x18/29-5/11x8/29+5/11x19/29

=5/11x(18/29-8/29+19/29)

=5/11x1=5/11

XxX = 68 - 20 : 5

XxX = 68 - 4

XxX = 64

=> X = 8

Yxy =25 + 8 x 3 

YxY = 25 + 24

YxY = 49

=> Y = 7

XxX=68-4

XxX=64

vì 64=8x8 nên x=8.

yxy=25+24

yxy=59

59 ko bằng số nào nhân số nào nên y ko có giá trị .

\(8x^3+12x^2y+6xy^2+y^3-z^3\)

\(=\left(2x+y\right)^3-z^3\)

\(=\left(2x+y-z\right)\left[4x^2+z\left(2x+y\right)+z^2\right]\)

a, 8a3 - 36a2 +54ab2 - 27b3

=(8a3-36a2b +54ab2 - 27b3)

=(2a-3b)2

=(2a-3b)(2a-3b)(2a-3b)

b, 8x3 + 12x2y + 6xy2 + y3 - z 3

=(8x3 + 12x2y + 6xy2 + y3) - z3

=(2x + y)3 - y3

=(2x + y +z) . [ (2x + Y)2 + 2(2x + y)+ z2

= (2x + y + z)(4x2 + 4xy + y2 + 4x + 2y + z2

\(\frac{2}{5}\times\frac{3}{8}+\frac{3}{4}=\frac{2\times3}{5\times8}+\frac{3}{4}=\frac{1\times3}{5\times4}+\frac{3}{4}=\frac{3}{20}+\frac{3}{4}=\frac{3}{20}+\frac{15}{20}=\frac{18}{20}=\frac{9}{10}\)

\(\frac{2}{5}+\frac{3}{8}\times\frac{3}{4}=\frac{2}{5}+\frac{9}{32}=\frac{64}{160}+\frac{45}{160}=\frac{109}{160}\)

Hai bài kia tương tự

\(a,=8\left(x^3-125\right)=8\left(x-5\right)\left(x^2+10x+25\right)\\ b,=\left(0,1+4x\right)\left(0,01-0,4x+16x^2\right)\\ d,=\left(3x-\dfrac{1}{2}y\right)\left(9x^2+\dfrac{3}{2}xy+\dfrac{1}{4}y^2\right)\\ c,=\left(\dfrac{1}{5}y+x\right)\left(\dfrac{1}{25}y^2-\dfrac{1}{5}xy+x^2\right)\)

a, 8x³- 1000 = (2x)³ - 10³ = (2x -10). (4x² + 20x +100)

b,\(0,001+64x^3=\left(\dfrac{1}{10}\right)^3+\left(4x\right)^3=\left(\dfrac{1}{10}+4x\right).\left(\dfrac{1}{100}-\dfrac{2}{5}x+16x^2\right)\)

c, \(\dfrac{1}{125}y^3+x^3=\left(\dfrac{1}{5}y\right)^3+x^3=\left(\dfrac{1}{5}y+x\right).\left(\dfrac{1}{25}y^2-\dfrac{1}{5}yx+x^2\right)\)

\(d,27x^3-\dfrac{1}{8}y^3=\left(3x\right)^3-\left(\dfrac{1}{2}y\right)^3=\left(3x-\dfrac{1}{2}y\right).\left(9x^2+\dfrac{3}{2}xy+\dfrac{1}{4}y^2\right)\)

\(\frac{1}{3}.\frac{5}{2}.2.\frac{2}{5}.\frac{4}{8}.3\)

\(=\left(\frac{1}{3}.3\right).\left(\frac{5}{2}.\frac{2}{5}\right).\left(2.\frac{4}{8}\right)\)

\(=1.1.1=1\)

tự tính