−3(10−(3−8)+4−2²-−3(4−9))
=−3(10−(−5)+4−2²-−3(4−9))
=−3(15+4−2²-−3(4−9))
=−3(19−2²-−3(4−9))
=−3(19−4−3(4−9))
=−3(15−3(4−9))
=−3(15−(3)(−5))
=−3(15−(−15))
=(−3)(30)
=−90
