б)<span> ℓog2x+3(5x2+11x+3)=2</span>
<span>5x²+11x+3=(2x+3)²</span>
<span>5x²+11x+3=4x²+12x+9</span>
<span>5x²+11x+3-4x²-12x-9=0</span>
<span>x²-x-6=0</span>
<span>D = 1²-4*1*(-6)=1+24=25</span>
<span>x1=(1+5)/2=3</span>
<span>x2=(1-5)/2=-2</span>
(1 24/25)^5 * 5^11/7^10=
=((49/25)^5 * 5^11)/7^10=
=(7^10/5^10*5^11)/7^10=
=(7^10*5)/7^10=
=5
Y=5x²+2x-7
при x=1;-2
y(1)=5•1²+2•1-7=0
y(-2)=5•(-2)²+2•(-2)-7=5•4-4-7=9
B(n-1)=(n-1)²+1=n²-2n+2
b(n)=n²+1
b(n+1)=(n+1)²+1=n²+2n+2
5*(-4)-111=(-20)-111=-131
5,71*(0,09)-0,71*0,09= 0,5139-0,0639=0,45