Ta có :
\(A=13a+19b+4a-2b\)
\(\Leftrightarrow A=\left(13a+4a\right)+\left(19b-2b\right)\)
\(\Leftrightarrow A=17a+17b\)
\(\Leftrightarrow A=17\left(a+b\right)=17.100=1700\)
Giải:
Ta có:
\(A=13a+19b+4a-2b\)
\(=a\left(13+4\right)+b\left(19-2\right)\)
\(=a.17+b.17\)
\(=17\left(a+b\right)\)
\(=17.100\)
\(=1700\)
Vậy \(A=1700\)