Answers

2014-06-12T12:14:21+08:00
(40+1)(40+1)

Solution:
=(40)(40)+2(40)+(1)(1)
=1600+80+1
=1681

(50+7)(40+3)

Solution:
FOIL METHOD
=(50)(40)+(150+280)+(7)(3)
=2000+430+21
=2451

(30+9)(30+9)

Solution:

=(30)(30)+2(270)+(9)(9)
=900+540+81
=1521
0
sorry but this is not special product.(50+7)(40+3) <--- not special product...
Right, if we relate it to polynomials it will be just a quadratic polynomial.
2014-06-12T17:28:41+08:00
1.) 
special product: Formula
(x-y)²=x²-2xy+y²

(50-9)²=50²-2(50)(9)+9²
(50-9)²=1681

2.)
special product: Formula
(x+y)(x-y)=x²-y²

(50+7)(50-7)=50²-7²
(50+7)(50-7)=2451

3.)
special product: Formula
(x+y)²=x²+2xy+y²

(30+9)²=30²+2(30)(9)+9²
(30+9)²=1521
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