Question

докажите тождество (1,4a^3-5b^2) (1,4a^3+5b^2)-2,96a^6+25b^4=-а^6

Answer 1

(1,4a³-5b²) (1,4a³+5b²)-2,96a⁶+25b⁴=-а⁶
(1,4а³)² - (5b²)²- 2,96a⁶+25b⁴= 1,96a⁶-25b⁴- 2,96a⁶+25b⁴=-2,96a⁶+1,96a⁶=
=a⁶(-2,96+1,96)=-1a⁶=-a⁶
применили формулу   (а-в)(а+в)=а²-в²