Bài 1: Tìm x biết :
a) x/5=2/3 b) x/3 – 1/2 = 1/5 c) x/5 + 1/2 = 6/10 d) x+2/15 = 1/3 e)x-12/4 = 1/2
Bài 1: Tìm x biết : a) x/5=2/3 b) x/3 – 1/2 = 1/5 c) x/5 + 1/2 = 6/10 d) x+2/15 = 1/3 e)x-12/4 = 1/2
By Parker
Đáp án:
a)
` => (3x)/15 = 10/15`
` => 3x = 10`
` => x = 10/3
b)
` x/3 – 1/2 = 1/5`
` x /3 = 1/5 + 1/2 = 7/10`
` => (10x)/30 = 21/30`
` => 10x = 21`
` => x = 21/10`
c)
` x /5 +1/2 = 6/10`
` => x/5 = 1/10`
` => (2x)/10 = 1/10`
` => 2x = 1`
` => x =1/2
d)
` x +2/15 = 1/3`
` x = 1/3 -2/15`
` x = 1/5`
e)
` x -12/4 = 1/2`
` x = 1/2 + 12/4`
` x = 7/2`
Đáp án:
Giải thích các bước giải:
a.
⇔3.x=5.2
⇔3x=10
⇔x=$\frac{10}{3}$
b.
⇔$\frac{x}{3}$ = $\frac{1}{5}$ + $\frac{1}{2}$
⇔$\frac{x}{3}$ = $\frac{7}{10}$
⇔10.x=3.7
⇔10x=21
⇔x=$\frac{21}{10}$
c.
⇔$\frac{x}{5}$ = $\frac{6}{10}$ – $\frac{1}{2}$
⇔$\frac{x}{5}$ = $\frac{1}{10}$
⇔10.x=5.1
⇔10x=5
⇔x=$\frac{1}{2}$
d.
⇔x=$\frac{1}{3}$ – $\frac{2}{15}$
⇔x=$\frac{1}{5}$
e.
⇔x=$\frac{1}{2}$ + $\frac{12}{4}$
⇔x=$\frac{7}{2}$