N2 a) 3^4-(-1)^4=81-1=80
b)(-3,3)^3-0,027=(-10/3)^3-27/1000=-1000/27-27/1000=-1000729/27000
v) (-7^2)×(-2/7)^2=-(7×2/7)^2=-2^4=-4
a) 2^2-(-3)^2=4-9=-5
b)(-2,5)^3×0,064=-(5/2)^3×(2/5)^3=-(5/2×2/5)^3=-1^3=-1
v)(-5^1)×(-2/5)^4=(-5)×(2/5)^4=-5×16/625=-0,128
-3x+1+(x-5)=5(3-x)+5.
-3x+1+x-5=15-5x+5.
-3x+x+5x=15+5-1+5.
3x=24.
x=24:3.
x=8.