ơ

Rõ ràng có câu hỏi mà

bn đăng lại ik

a) x - 3/4 = 1/7

x = 1/7 + 3/4

x = 25/28

b) 15/x - 1/3 = 28/51

15/x = 28/51 + 1/3

15/x = 45/51

x = 15.51/45

x = 17

a: =>x+41=7/4

hay x=-157/4

a) 4(x+41)=7
x+41=7/4
x=7/4-41
x=157/4
b) có gì đó sai sai-.-

Bài 1:

x/-3=9/4

nên x=-9/4*3=-27/4

2x+y=-4

=>y=-4-2x=-4-2*(-27/4)=-4+27/2=27/2-8/2=19/2

j HGBYH B

Giải:

\(\dfrac{15}{x}-\dfrac{1}{3}=\dfrac{28}{51}.\)

\(\dfrac{15}{x}=\dfrac{28}{51}+\dfrac{1}{3}.\)

\(\dfrac{15}{x}=\dfrac{28}{51}+\dfrac{17}{41}.\)

\(\dfrac{15}{x}=\dfrac{15}{17}\Rightarrow x=17.\)

Vậy.....

~ Học tốt!!! ~

\(a,\dfrac{-1}{8}=\dfrac{3}{x}\\ \dfrac{3}{-24}=\dfrac{3}{x}\\ x=-24\\ b,\dfrac{x}{3}=\dfrac{3}{x}\\ x.x=3.3\\ x^2=9\\ x=\pm3\\ c,\dfrac{3}{4}.x=1\dfrac{1}{2}\\ \dfrac{3}{4}.x=\dfrac{3}{2}\\ x=\dfrac{3}{2}:\dfrac{3}{4}\\ x=2\\ d,x-\dfrac{3}{10}=\dfrac{7}{15}:\dfrac{3}{5}\\ x-\dfrac{3}{10}=\dfrac{7}{9}\\ x=\dfrac{7}{9}+\dfrac{3}{10}\\ x=\dfrac{97}{90}\\ e,\dfrac{-4}{7}-x=\dfrac{-8}{3}.\dfrac{3}{7}\\ \dfrac{-4}{7}-x=\dfrac{-8}{7}\\ x=\dfrac{-4}{7}+\dfrac{8}{7}\\ x=\dfrac{4}{7}\\ \)

fan liver tốt ghê

A)  7/38 x 9/11 +7/38 x 4/11 -7/38 x 2/11

=7/38.(9/11+4/11-2/11)

=7/38

B) 5/31 x 21/25 + 5/31 x -7/10 - 5/31 x 9/20

=5/31.(21/25-7/10-9/20)

=5/31.(-31/100)

=-1/20