\(\frac{7}{8}+\frac{1}{8}\times\frac{3}{8}+\frac{1}{8}\times\frac{5}{8}=\frac{7}{8}+\frac{1}{8}\times\left(\frac{3}{8}+\frac{5}{8}\right)=\frac{7}{8}+\frac{1}{8}\times1\)

\(=\frac{7}{8}+\frac{1}{8}=1\)

=1/8 x ( 7/8 +5/8)

= ...

ban tu lam not nha

       Bài làm :

Ta có :

\(\frac{7}{8}+\frac{1}{8}\times\frac{3}{8}+\frac{1}{8}\times\frac{5}{8}\)

\(=\frac{7}{8}+\frac{1}{8}\times\left(\frac{3}{8}+\frac{5}{8}\right)\)

\(=\frac{7}{8}+\frac{1}{8}\times\frac{8}{8}\)

\(=\frac{7}{8}+\frac{1}{8}\times1\)

\(=\frac{8}{8}=1\)

\(=8\left(x^3-\dfrac{1}{64}\right)=8\left(x-\dfrac{1}{4}\right)\left(x^2+\dfrac{1}{4}x+\dfrac{1}{16}\right)\)

8x7+8x3+8+2

=8x7+8x3+8x1+2

=8x(7+3+1)+2

=8x11+2

=88+2

=90

90 k mik nha

=8 x (7+3+2)

= 8 x 12

= 96

Bài làm

a) \(\frac{8}{11}x\left(\frac{7}{4}-\frac{3}{8}\right)\)

\(=\frac{8}{11}x\left(\frac{14}{8}-\frac{3}{8}\right)\)

\(=\frac{8}{11}x\frac{11}{8}\)

\(=\frac{88}{88}\)

\(=1\)

b) \(\frac{15}{6}:\left(\frac{3}{8}x\frac{3}{5}\right)\)

\(=\frac{15}{6}:\frac{9}{40}\)

\(=\frac{15}{6}x\frac{40}{9}\)

\(=\frac{600}{54}\)

\(=\frac{100}{9}\)

a=1;b=100:9

\(8x^3-\frac{1}{8}\)

\(=\left(2x\right)^3-\left(\frac{1}{2}\right)^3\)

\(=\left(2x-\frac{1}{2}\right)\left(4x^2+x+\frac{1}{4}\right)\)

tích hộ

\(a,=\left(x+1\right)^2\\ b,=\left(3x-y\right)^2\\ c,=\left(x-3\right)\left(x+3\right)\\ d,=\left(x+4\right)^3\\ e,=\left(x-2\right)^3\\ f,=\left(x+2\right)\left(x^2-2x+4\right)\\ g,=\left(2x-y\right)\left(4x^2+2xy+y^2\right)\)

\(a,=8\left(x^3-125\right)=8\left(x-5\right)\left(x^2+5x+25\right)\\ b,=\left(0,1+4x\right)\left(0,01-0,4x+16x^2\right)\\ c,=\left(x+\dfrac{1}{5}y\right)\left(x^2-\dfrac{1}{5}xy+\dfrac{1}{25}y^2\right)\\ d,=\left(3x-\dfrac{1}{2}y\right)\left(9x^2+\dfrac{3}{2}xy+\dfrac{1}{4}y^2\right)\\ e,=\left(x-1+3\right)\left[\left(x-1\right)^2-3\left(x-1\right)+9\right]\\ =\left(x+2\right)\left(x^2-2x+1-3x+3+9\right)\\ =\left(x+2\right)\left(x^2-5x+13\right)\\ f,=\left(\dfrac{x^2}{2}-y^2\right)\left(\dfrac{x^4}{4}+\dfrac{x^2y^2}{2}+y^4\right)\)