=9,8 * 43 + 19 * 9,8 - 61 * 9,8
= 9,8 * (43+19-61)
=9,8 * (62-61)
=9,8*1
=9,8
\(9,8\times43+2\times19\times4,9-6,1\times9,8\)
\(=9,8\times43+19\times\left(2\times4,9\right)-6,1\times9,8\)
\(=9,8\times43+19\times9,8-61\times9,8\)
\(=9,8\times\left(43+19-61\right)\)
\(=9,8\times\left(62-61\right)\)
\(=9,8\times1\)
\(=9,8\)