Question

[ɣ/ղ✿ʑคภg✿♄ồ‿]

Tìm x là số tự nhiên biết : 

a) \(\frac{x}{17}=\frac{60}{204}\)  b) \(\frac{6+x}{33}=\frac{7}{11}\) c) \(\frac{12+x}{43-x}=\frac{2}{3}\)

d)\(\frac{x}{5}< \frac{3}{7}\) e) \(1< \frac{11}{x}< 2\) g) \(\frac{15}{26}+\frac{x}{16}=\frac{46}{52}\)

HELP ME !

Answer 1

[Trần_Hiền_Mai]

a)\(\frac{x}{17}=\frac{60}{204}=\frac{5}{17}\Rightarrow x=5\)

b)\(\frac{6+x}{33}=\frac{7}{11}\Rightarrow11\left(6+x\right)=7.33\Rightarrow11.6+11x=231\Rightarrow66+11x=231\)

\(\Rightarrow11x=231-66\Rightarrow11x=165\Rightarrow x=\frac{165}{11}=15\)

c)\(\frac{12+x}{43-x}=\frac{2}{3}\Rightarrow2\left(43-x\right)=3\left(12+x\right)\Rightarrow2.43-2x=3.12+3x\)

\(86-2x=36+3x\Rightarrow86-36=3x+2x\Rightarrow50=5x\Rightarrow x=\frac{50}{5}=10\)