1*15 2*14 3*13 4*12 5*11 6*10 7*9 8*8怎樣計算簡便

1*15 2*14 3*13 4*12 5*11 6*10 7*9 8*8怎樣計算簡便


1*15=（8-7）*（8+7）=8^2-7^2=64-49=15
2*14=（8-6）*（8+6）=8^2-6^2=64-36=28
.
7*9=（8-1）*（8+1）=8^2-1^2=64-1=63
8*8=8^2=64
a^b意思是a的b次方



25×【4×12】×7簡便計算


=（25x4）X（12X7）=100X84 =8400



用遞等式計算（能簡便計算的要簡便計算）35,4-12.5÷25+1.7


35,4-12.5÷25+1.7
=35+4/10-1（2+1/2）/25+17/10
=35+4/10-25/2/25+17/10
=35+4/10-5/10+17/10
=35+16/10
=36.6



14/25×12+7/25×14+42/25×2簡便運算


14/25×12+7/25×14+42/25×2
＝12×14/25+7×14/25+6×14/25
＝（12+7+6）×14/25
＝25×14/25
＝14

Elden Ring Premiere

RELATED INFORMATIONS