Question

Stosując wzory skróconego mnożenia oblicz
a) (x + 3)² - (x + 2)² =
b) (2x - 1) × (2x + 1) =
c) (x + 1
2)² =
d) (5 - b)² + (2 + b)² =

Answer 1

a) (x + 3)² - (x + 2)² =x²+6x+9-x²-4x-4=6x-4x+9-4=2x+5

b) (2x - 1) × (2x + 1) =(2x)²-1²=4x²-1

c) (x + 12)² =x²+2x·12+12²=x²+24x+144

d) (5 - b)² + (2 + b)² =25-10b+b²+4+4b+b²=b²+b²-10b+4b+25+4=2b²-6b+29

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(a+b)²=a²+2ab+b²

(a-b)(a+b)=a²-b²