Dane wyrażenie doprowadź do jak najprostrzej postaci i oblicz wartość liczbową dla a = - 3 i b = - 1 a² - b² _____________ 3a² - 6ab + 3b²

a² - b²..............(a-b)(a+b).......(a-b)(a+b)......a+b .......-3-1...... -4 _____________ = ---------------- =-------------- = ---------- =----------- =----=2/3 3a² - 6ab + 3b²....3(a2-2ab+b2) ....3(a-b)2 .......3(a-b)....3*(-3+1)... -6

(a² - b²):(3a² - 6ab + 3b²)=[(a-b)(a+b)]:[3( a²-2ab+b²)]=[(a-b)(a+b)]:[3(a-b)²]=(a+b)/[3(a-b)] a =-3 b =-1 a+b=(-3)+(-1)=-4 3*[(-3)-(-1)]=3*[(-3)+1]=3*(-2)=-6 (a+b)/[3(a-b)]=(-4)/(-6)=2/3

a² - b² _____________ 3a² - 6ab + 3b² = (-3)²-(-1)²/3*(-3)²-6*(-3)*(-1)+3*(-1)²= 9-1/27-18+3=8/12=2/3 ;))