Question

Tìm x biết:

a) (2x-4).(3x+12)=0

b) 697:\(\frac{15x+364}{x}\)=17

Answer 1

a, \(\left(2x-4\right)\left(3x+12\right)=0\)

\(\Rightarrow\orbr{\begin{cases}2x-4=0\\3x+12=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}2x=4\\3x=-12\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=2\\x=-4\end{cases}}\)

b, \(697\div\frac{15x+364}{x}=17\)

\(\Rightarrow\frac{15x+364}{x}=697\div17\)

\(\Rightarrow\left(15x+364\right)\div x=41\)

\(\Rightarrow15x+364=41x\)

\(\Rightarrow15x-41x=-364\)

\(\Rightarrow-26x=-364\)

\(\Rightarrow x=-364\div\left(-26\right)\)

\(\Rightarrow x=14\)