a)\(\frac{x+7}{x}=\frac{4}{5}\)
=>5(x+7)=4x
5x+35=4x
5x-4x=-35
x=-35
Vậy x=-35
b)(x-20)/(x+40)=(x+70)/(x-10)
(x-20)*(x-10)=(x+40)*(x+70)
x(x-10)-20(x-10)=x(x+70)+40(x+70)
x2-10x-20x+200=x2+70x+40x+2800
x2-x2-10x-20x-70x-40x=2800-200
0-(10x+20x+70x+40x)=2600
-140x=2600
x=2600/(-140)
x=\(-\frac{130}{7}\)
Vậy x=-130/7
bài 1
a,(x+7) :x=4:5
b,(x-20):(x+40)=(x+70):(x-10)
bài 1
a,(x+7) :x=4:5
b,(x-20):(x+40)=(x+70):(x-10)
Tìm x, biết:
a) (x+15) : x = 4:3
b) (x-20) : (x-10) = (x+40) : (x+70)
Tìm x, biết: (x-20):(x-10)=(x+40):(x+70)
Tìm x, biết :
a) (x + 15) : x = 4:3
b) (7,5 - x) : (3,5 + x) = 5:6
c) (x - 20) : (x - 10) = (x + 40) : (x + 70)
Tìm x biết:
a, (x+15):x =4:3
b, (7,5-x) :(3,5+x)= 5:6
c, (x+20):(x-10)=(x+40):(x+70)
Tìm x biết:
(x-20)÷(x-10)=(x+40)÷(x+70)
\(\frac{x-20}{x-10}=\frac{x+40}{x+70}\)
Tìm x biết:
(x - 20) : ( x + 40)= ( x -10) : ( x +70)
