Question

Zapisz w najkrótszej postaci

(2a + 1)²-4(a-2)(a+2)=

(2b+a)²+2(a-2b)²-(a+2b)(a-2b)+4ab=

(x+3y)(x-3y)+(x+2y)²-(2x²-5y)²=

Answer 1

4a^2+4a+1 -4(a^2-4)= 4a^2+4a+1 -4a^2+16=4a+17

4b^2+4ab+a^2 +2(a^2-4ab+4b^2) -(a^2-4b^2) +4ab=4b^2+4ab+a^2 +2a^2-8ab+8b^2 -a^2+4b^2 +4ab= 16b^2+2a^2

x^2-9y^2 +x^2+4xy+4y^2 -4x^4+20x^2y-25y^2=2x^2-30y^2+4xy-4x^4+20x^2y

Answer 2

(2a + 1)²-4(a-2)(a+2)=(2a)²+2*2a*1+1²-4a²-2²= 4a²+4a+1-4a²-4= 4a-3

(2b+a)²+2(a-2b)²-(a+2b)(a-2b)+4ab=(2b)²+2*2b*a+a²+2*a²-2*a*(-2b)+(2b)²=4b²+4ab+a²-4a²-2a*(-2b)+4b²= -3a²+8b²+8ab

(x+3y)(x-3y)+(x+2y)²-(2x²-5y)²=x²-(3y)²+x²+2*x*2y+(2y)²-(2x²)²-2*2x²*(-5y)-(5y)²=x²-9y²+x²+4xy+4y²-2x⁴+20xy-25y²=-2x⁴+2x²-30y²+24xy