计算49×51-2499(利用公式速算)
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/14 10:21:32
![计算49×51-2499(利用公式速算)](/uploads/image/z/241091-35-1.jpg?t=%E8%AE%A1%E7%AE%9749%C3%9751-2499%EF%BC%88%E5%88%A9%E7%94%A8%E5%85%AC%E5%BC%8F%E9%80%9F%E7%AE%97%EF%BC%89)
xRAj0M-%aDe?%`? {)ĄK(J^[br4[H)îվ\)k_{yy5;*
eD2$
;!0fɤuRTPOM5+,78Sy0)aK|xLkV:k@dކxMK04Bfn+"^u*optQ\癵=Qc7cWh?W0n#@@sY;9N
计算49×51-2499(利用公式速算)
计算49×51-2499(利用公式速算)
计算49×51-2499(利用公式速算)
49*51-2499=(50+1)*(50-1)-2499=50^2-1^2-2499=2500-1-2499=0
公式:(a+b)(a-b)=a^2-b^2
=(50-1)*(50+1)-2499
=50^2-1-2499
=2500-1-2499
=0
49×51-2499
=(50-1)(50+1)-2499
=2500-1-2499
=2500-(1+2499)
=2500-2500
=0
49×51-2499
=(50-1)×(50+1)-2499
=50^2-1-2499
=2500-2500
=0
49×51-2499
=49*(50+1)-2499
=49*50+49*1-2499
=2450+49-2499
=2499-2499
=0
(50+1)(50-1)-2499=0
49×51-2499
=(50-1)(50+1)-(50²-1)
=50²-1-50²+1
=0