lần này mới được à

? Lần này mới được

a: =6x2/5-3/10

=12/5-3/10

=24/10-3/10=21/10

b: =1/2+4/3=3/6+8/6=11/6

c: =5/6+1/4=10/12+3/12=13/12

\(\frac{2}{3}+\frac{3}{4}:\frac{6}{7}+\frac{1}{8}.\frac{4}{3}\)

=\(\frac{2}{3}+\frac{3}{4}.\frac{7}{6}+\frac{1}{8}.\frac{4}{3}\)

=\(\frac{2}{3}+\frac{7}{8}+\frac{1}{6}\)

=\(\left(\frac{2}{3}+\frac{1}{6}\right)+\frac{7}{8}\)

=\(\frac{5}{6}+\frac{7}{8}\)

=\(\frac{41}{24}\)

=(4x0.25)x(2x0.5)

=1x1=1

Bạn ơi không gửi linh tinh nhé

2017 nhé

Bài 1: 

a: x+1/2=5/6

nên x=5/6-1/2=1/3

b: x+1/4=3/4

nên x=3/4-1/4=2/4=1/2

c: x+3/10=1/2

nên x=1/2-3/10=5/10-3/10=1/5

d: x+1/4=3/8

nên x=3/8-1/4=3/8-2/8=1/8

TOT LAM

\(a,\dfrac{3}{2}\times\dfrac{4}{5}\times\dfrac{2}{3}\times\dfrac{15}{4}\\ =\dfrac{3\times4\times2\times15}{2\times5\times3\times4}\\ =\dfrac{3\times4\times2\times5\times3}{2\times5\times3\times4}\\ =3\)

\(b,\dfrac{6}{7}\times\dfrac{5}{8}\times\dfrac{7}{3}\times\dfrac{7}{6}\times\dfrac{8}{5}\\ =\dfrac{6\times5\times7\times7\times8}{7\times8\times3\times6\times5}\\ =\dfrac{7}{3}\)

a) \(\dfrac{3}{2}\times\dfrac{4}{5}\times\dfrac{2}{3}\times\dfrac{15}{4}\)

\(=\left(\dfrac{3}{2}\times\dfrac{2}{3}\right)\times\left(\dfrac{4}{5}\times\dfrac{15}{4}\right)\)

\(=1\times3\)

\(=3\)

b) \(\dfrac{6}{7}\times\dfrac{5}{8}\times\dfrac{7}{3}\times\dfrac{7}{6}\times\dfrac{8}{5}\)

\(=\left(\dfrac{6}{7}\times\dfrac{7}{6}\right)\times\left(\dfrac{5}{8}\times\dfrac{8}{5}\right)\times\dfrac{7}{3}\)

\(=1\times1\times\dfrac{7}{3}\)

\(=\dfrac{7}{3}\)

Chúc bạn học tốt

1:

a: \(A=2+3\sqrt{x^2+1}>=3\cdot1+2=5\)

Dấu = xảy ra khi x=0

b: \(B=\sqrt{x+8}-7>=-7\)

Dấu = xảy ra khi x=-8

\(2\frac{4}{5}\)+3:\(\frac{3}{8}\)

=14/5+3*8/3

=14/5+8

=54/5

2>

x + 6/7=1/2*3

x+6/7=3/2

x=3/2-6/7

x=21/14-12/14

x=9/14

vậy x=9/14