a.
\(\left(100+42\right)\times42+\left(200-58\right)\times58=142\times42+142\times58=142\times\left(42+58\right)=142\times100=14200\)
b.
\(\left(1998\div18-1443\div13\right)\times\left(16996-1110\div30\times305\right)=\left(111-111\right)\times\left(16996-1110\div30\times305\right)\)
\(=0\times\left(16996-1110\div30\times305\right)=0\)
c.
\(5^3_5+1,75+6^1_8+4^1_4+3,875+3,4=5,6+1,75+6,125+4,25+3,875+3,4\)
\(=\left(5,6+3,4\right)+\left(1,75+4,25\right)+\left(6,125+3,875\right)=9+6+10=25\)
a)(100+42)x42+(200-58)x58
=142x42-142x58
=(42-58)x142
=(-16).142
=-2272
b)(1998:18-1443:13)x(16996-1110:30x305)
=(111-111)x(16996-1110:30x305)
=0x(16996-1110:30x305)
=0
c)\(5\frac{3}{5}\)+1,75+\(6\frac{1}{8}\)+\(4\frac{1}{4}\)+3,875+3,4
=(1,75+\(4\frac{1}{4}\))+(3,875+\(6\frac{1}{8}\))+(3,4+\(5\frac{3}{5}\))
=6+10+9
=25