Lg5=log5(5)/log5(10)=1/log5(10)
log5(0.25)=log5(5^2*10^(-2))=2-2log5(10)=2-2*1/0.699≈-0.861
(6x−9y)⋅(6x+9y)−36x² = 36х² - 81у²-36х² = -81у² = -81(0,1)² = -0,81
3x(2x-1)=0
x1=0
x2=1/2
x²=1/25
x1=1/5
x2=-1/5
4x²-7x-2=0
D=49-4*4*2=49-32=17
x1=7+√17/8
x2=7-√17/8