Question

简便方法计算：15.8x5.8+4.2x4.2+11.6x4.2

Answer 1

15.8x5.8+4.2x4.2+11.6x4.2=15.8X5.8+4.2X(11.6+4.2)=15.8X5.8+4.2X15.8=10*15.8=158

Answer 2

15.8×5.8+4.2×（4.2+11.6）
=15.8×5.8+4.2×15.8
=15.8+（4.2+5.8）
=15.8×10
=158

Answer 3

=15.8*5.8+4.2*(4.2+11.6)=15.8*(5.8+4.2)=15.8*10=158