Question

Вычислить, используя формулу (a-b)(a+b)=a^2-b^2.... (x^2+2)(x^2-2)+... (y-a^2)(y+a^2)=... (a^2-4)(a^2+4)=.... (x^3+5)(x^3-5)=... (ab-c)(ab+c)=.... (1-xy)(xy+1)=....

Answer 1

 

(x^2+2)(x^2-2)=x^{4}-4

(y-a^2)(y+a^2)=y^{2}-a^{4}

(a^2-4)(a^2+4)=a^{4}-16

(x^3+5)(x^3-5)=x^{6}-25

(ab-c)(ab+c)=a^{2}b^{2}-c^{2

(1-xy)(xy+1)=1-x^{2}y^{2

Answer 2

$(x^2+2)(x^2-2)=x^4-4\\ (y-a^2)(y+a^2)=y^2-a^4\\ (a^2-4)(a^2+4)=a^4-16\\ (x^3+5)(x^3-5)=x^6-25\\ (ab-c)(ab+c)=a^2b^2-c^2\\ (1-xy)(xy+1)=1-x^2y^2$