1) a)3x-1=-10 3x=-10+1 3x=-9 x= -3
b) -2x+4=x-5
-2x-x=-5-4
-3x=-9
3x=9
x=3
c)4(x+2)=3(x-1)
4x+8=3x-3
4x-3x=-3-8
x=-11
d)a=2
b=-5
c=2
Δ= 25 -4*2*2= 25 -16=9
x1, x2= (-5 -/+ √9)/2*2= (-5 -/+ 3)/4
x1=(-5+3)/4= - 2/4= -1/2
x2= (-5-3)/4= -8/4= -2
(x+1/2)(x+2)=0
x+1/2=0 x+2=0
x=-1/2 x=-2
a+c=65
c+b=52
a+b=47
2a+2b+2c=65+52+47
2(a+b+c)=164
a+b+c=82
b=82-65=17
a=82-52=30
c=82-47=35