Question

DAU COROANA!!!!

Folosind dormulele de calcul prescurtat, sa se calculeze:
a. (x + 1)² - 2(x - 1)² -3(x +1)(x - 1)
b. 4(2m + n)² - 3(m - 4n)² + 3(m + 2n)(2n - m)
c. (2a +3b)² - (2a - 3b)² - (2a + 3b)(2a - 3b)
d. (a + b)(a - b)(a² + b²)(a⁴ +b²)(a⁴ + b⁴)

Answer 1

A). …=x^2+2x+1-2(x^2-2x+1)-3(x^2-1)=x^2+2x+1-2x^2+4x-2-3x^2+3=-4x^2+6x+2
B). …=4(4m^2+4mn+n^2)-3(m^2-8mn+16n^2)+(3m+6n)(2n-m)=16m^2+16mn+4n^2-3m^2+24mn-48n^2+6mn-3m^2+12n^2-6mn=10m^2+40mn-32n^2
C). …=[2a+3b-(2a-3b)]•(2a+3b+2a-3b)-(4a^2-9b^2)=(2a+3b-2a+3b)•4a-4a^2+9b^2=6b•4a-4a^2+9b^2=24ab-4a^2+9b^2
D). …=(a^2-b^2)•(a^2+b^2)•(a^4+b^2)(a^4+b^4)=(a^4-b^4)•(a^4+b^2)•(a^4+b^2)=(a^8-b^8)•(a^4+b^2)=a^12+a^8b^2-a^4b^8-b^10