a) -7624+(1543+7624)
= -7624+1543+7624
=-7624+7624+1543
=0+1543
=1543
b) (25-514)-(486-73)
=25-514-486+73
=25+73-514-486
=100-1000
=-900
a) \(-7624+\left(1543+7624\right)\)
\(=\left(-7624+7624\right)+1543\)
\(=0+1543\)
\(=1543\)
b) \(\left(25-514\right)-\left(486-73\right)\)
\(=\left(25+73\right)-\left(514+486\right)\)
\(=98-1000\)
\(=-902\)
\(a\))\(-7624+\left(1543+7624\right)\)
\(=\left(-7624+7624\right)+1543\)
\(=0+1543\)
\(=1543\)