0

41 x 28 = (41)·(28) = (40 + 1)·(20 + 8)
= 8x100 + 32x10 + 2x10 + (    )
= 800 + 320 + 20 + (    ) =     1148

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FirstOuterInnerLast

 

Level

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How Many

5

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30

50

  

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