a)(x- $\frac{12}{7}$): $\frac{6}{5}$ = $\frac{4}{7}$
b) $\frac{0,13}{x}$ = $\frac{9}{42}$
c) $\frac{5}{x-2}$= $\frac{15}{6}$
a)(x- $\frac{12}{7}$): $\frac{6}{5}$ = $\frac{4}{7}$ b) $\frac{0,13}{x}$ = $\frac{9}{42}$ c) $\frac{5}{x-2}$= $\frac{15}{6}$
By Nevaeh
Đáp án: a)x=46/21
b)x=91/150
c)x=4
Giải thích các bước giải:
a)(x-12/7):6/5=4/7
=>x-12/7=(4/7).(5/6)
=>x-12/7=10/21
=>x=10/21+12/7
=>x=10/21+36/21
=>x=46/21
b)0,13/x=9/42
=>(0,13.42)/9=x
=>x=91/150
c)5/(x-2)=15/6
=>5.6/15=x-2
=>2=x-2
=>x=2+2=4
a, ( x- 12/7): 6/5= 4/7
( x- 12/7)= 4/7. 6/5
x- 12/7= 24/35
x= 24/35+ 12/7
x= 24/35+ 60/35
x= 84/35
x= 12/5
Vậy x= 12/5
b, $\frac{0,13}{x}$ =$\frac{9}{42}$
⇔ 0,13. 42= x. 9
⇔ 5, 46= x. 9
x= 9: 5, 46
x= $\frac{9}{5, 46}$
x= $\frac{3}{1,82}$
Vậy x= $\frac{3}{1,82}$ ( có thể làm thành 300/ 182 hay 150/ 91 em nha!)
c, $\dfrac{5}{x-2}$ =$\dfrac{15}{6}$
$\frac{15}{3.( x-2)}$ =$\frac{15}{6}$
⇒ 3.( x-2)= 6
3.x- 6= 6
3.x= 6+ 6
3.x= 12
x= 12: 3
x= 4
Vậy x= 4
Chúc học tốt!