70%.x + 0,3.x + x : 2 = 20
<=> x(70% + 0,3) + x : 2 = 20
<=> x + x : 2 = 20
<=> x.(\(\dfrac{1}{2}+1\)) = 20
<=> x.\(\dfrac{3}{2}=20\)
<=> x = \(\dfrac{40}{3}\)
@Khánh Linh
BT1: Tìm x, biết:
3) \(\dfrac{0,3.x+2,5}{x}-3=17\)
BT1: Tìm x, biết:
6) \(x^{20}+81x^{16}=0\)
Tìm x , biết
x+(x+1)+(x+2)+...+70+71=71
BT1: Tìm x, biết:
4) \(\dfrac{\left(x+1\right)^2}{2}=\dfrac{4}{x+1}\)
BT1: Tìm x, biết:
3) \(\dfrac{x-1}{2}=\dfrac{8}{x-1}\)
BT1: Tìm x, biết
3) \(x:\dfrac{1}{2}+x:\dfrac{1}{4}+x:\dfrac{1}{8}+...+x:\dfrac{1}{512}=511\)
tìm x
x+20-70*2=0
BT1: Tìm x, biết
4) \(\dfrac{x+1}{99}+\dfrac{x+2}{98}=\dfrac{x+3}{97}-1\)
BT1: Tìm x \(\in\) Z biết:
1) \(\dfrac{1-x}{2017}+\dfrac{2-x}{2016}=\dfrac{3-x}{2015}+\dfrac{4-x}{2014}\)
