Question

[không tên]

tim x biết x là số tự nhiên : a) \(\frac{6+x}{33}\)= \(\frac{7}{11}\) b)\(\frac{12+x}{43-x}\)=\(\frac{2}{3}\)

ai nhanh mk tick

Answer 1

[Nguyễn Tri Thúc]

a)33:11=3

7x3=21,21-6=15

x=15

Answer 2

[Hyuga Jiro]

a, \(\frac{6+x}{33}=\frac{7}{11}\)

\(\Leftrightarrow\left(6+x\right).11=7.33\)

\(\Leftrightarrow66+11x=231\)

\(\Leftrightarrow11x=231-66\)

\(\Leftrightarrow x=\frac{165}{11}=15\)

Vậy x = 15.

b,\(\frac{12+x}{43-x}=\frac{2}{3}\)

\(\Leftrightarrow3.\left(12+x\right)=2\left(43-x\right)\)

\(\Leftrightarrow36+3x=86-2x\)

\(\Leftrightarrow3x+2x=-36+86\)

\(\Leftrightarrow5x=50\)

\(\Leftrightarrow x=10\)

Vây x = 10.