100*79+(100+84)*21+84*29
=100*79+100*21+84*21+84*29
=100*(79+21)+84*(21+29)
=100*100+84*50
=10000+84*(100/2)
=10000+84*100/2
=10000+8400/2
=10000+4200
=14200
100*79+(100+84)*21+84*29
=100*79+100*21+84*21+84*29
=100*(79+21)+84*(21+29)
=100*100+84*50
=10000+84*(100/2)
=10000+84*100/2
=10000+8400/2
=10000+4200
=14200