答:
(2²+4²+6²+8²+10²)-(1²+3²+5²+7²+9²)
=(2²-1²)+(4²-3²)+(6²-5²)+(8²-7²)+(10²-9²)
=(2-1)×(2+1)+(4-3)×(4+3)+(6-5)×(6+5)+(8-7)×(8+7)+(10-9)×(10+9)
=3+7+11+15+19
=22+22+11
=55
解:
(2²+4²+6²+8²+10²)-(1²+3²+5²+7²+9²)
=2²+4²+6²+8²+10²-1²-3²-5²-7²-9²
=2²-1²+4²-3²+6²-5²+8²-7²+10²-9²
=(2+1)(2-1)+(4+3)(4-3)+(6+5)(6-5)+(8+7)(8-7)+(10+9)(10-9)
=3+7+11+15+19
=10+11+19+15
=40+15
=55
(2²+4²+6²+8²+10²)-(1²+3²+5²+7²+9²)
=(2²-1²)+(4²-3²)+(6²-5²)+(8²-7²)+(10²-9²)
=(2+1)(2-1)+(4+3)(4-3)+(6+5)(6-5)+(8+7)(8-7)+(10+9)(10-9)
=3+7+11+15+19
=55