0

77 x 71 = (77)·(71) = (70 + 7)·(70 + 1)
= (   )x100 + 7x10 + 49x10 + 7
= (   )x100 + 70 + 490 + 7 =     5467

0

41

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FirstOuterInnerLast

 

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How Many

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FOIL method @

 

Example >>>

 34 x 52 =  (30 + 4)·(50 + 2)

 

 

 

 

First

(A + B)·(C + D) = AC + AD + BC + BD

= 30 x 50

= 1500

Outer

(A + B)·(C + D) = AC + AD + BC + BD

= 30 x 2

=     60

Inner

(A + B)·(C + D) = AC + AD + BC + BD

= 4 x 50

=   200

Last

(A + B)·(C + D) = AC + AD + BC + BD

= 4 x 2

=       8

 

 

   

 

 

 

= 1768