1)4m²-16m-(m²-10m+25)=4m²-16m-m²+10m-25=3m²-6m-25
2) a)12x-1=2x-4
12x-2x=1+4
10x=5
x=2
b)2x²+6-8x-24=0
2x²-8x-18=0
2x²-8x=18
2x(x-4)=18
2x=18 x-4=18
x=9 x=22
g) x/5-x/3=2
x/5-x/3-2=0
3x-5x-30/15=0 умножим на 15
-2x-30=0
-2x=30
x=-15
3) 81x81=6561
b)?
4)a(a-b)/(a-b)(a+b)=a/a-b