Question

a)

3ab + 112 = ab7

b)

5ab +51 = ab2

c)

ab x aba = abab

Answer 1

a) \(3ab+112=ab7\Leftrightarrow112=7ab-3ab=4ab\Leftrightarrow ab=\dfrac{112}{4}=28\)

vậy \(ab=28\)

b) \(5ab+51=ab2\Leftrightarrow51=2ab-5ab=-3ab\Leftrightarrow ab=\dfrac{51}{-3}=-17\)

vậy \(ab=-17\)

c) \(ab.aba=abab\Leftrightarrow ababa=abab\Leftrightarrow ababa-abab=0\)

\(\Leftrightarrow abab\left(a-1\right)=0\) \(\Leftrightarrow\left\{{}\begin{matrix}abab=0\\a-1=0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=1\\bb=0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=1\\b=0\end{matrix}\right.\)

vậy \(a=1;b=0\)