25.3^2-24.7^2和1.25*14^2-125*8.6^2

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25.3^2-24.7^2和1.25*14^2-125*8.6^2

25.3^2-24.7^2和1.25*14^2-125*8.6^2
25.3^2-24.7^2和1.25*14^2-125*8.6^2

25.3^2-24.7^2和1.25*14^2-125*8.6^2
25.3^2-24.7^2
=(25.3+24.7)(25.3-24.7)
=50*0.6
=30
1.25*14^2-125*8.6^2
=1.25*14^2-1.25*100*8.6^2
=1.25*(14^2-100*8.6^2)
=1.25*(14^2-86^2)
=1.25*(14+86)(14-86)
=1.25*100*(-72)
=-9000

25.3^2-24.7^2
=(25.3-24.7)*(25.3+24.7)
=0.6*50
=30
1.25*14^2-125*8.6^2
=125*1.4^2-125*8.6^2
=125*(1.4^2-8.6^2)
=125*(1.4+8.6)*(1.4-8.6)
=125*10*(-7.2)
=125*8*(-0.9)*10
=1000*(-9)
=-9000