13x-12y=1411x-18y=4
78x-72y=84
44x-72y=16 *(-1)
34x=68
x=2
y=1
21-12√3=(2√3-3)²
√(2√3-3)²=|2√3-3|=2√3-3
1/(√13 -3 -√(21-12√3)=1/(√13 -3-2√3+3)=1/(√13-2√3)=
=(√13+2√3)/(√13-2√3)(√13+2√3)=(√13+2√3)/(13-12)=√13+2√3
Это просто
log8 (8^(-3)) = -3
log3 (1/27) = log3 (3^(-3)) = -3
lg 0,0001 = lg (10^(-4)) = -4
log√7 (49) =
log√7
((√7)^4) = 4
log3/2 (64/729) =
log3/2
(2^6/3^6) =
log3/2
((2/3)^6) = -6
log9 x = 1/2; x = 9^(1/2) = √9 = 3
log0,027 x = 2/3; x = (0,0027)^(2/3) = ((0,3)^3)^(2/3) = (0,3)^2 = 0,09