4х+1)-(7х+2)=х и 12х-9=с+5

Question

4х+1)-(7х+2)=х и 12х-9=с+5

Answer 1

4x+1-7x-2=x
-3x-1-x=0
-4x=1
x=-0,25
12x-9=c+5
12x=c+5+9
12x=c+14
x=c/12+7/6,c∈R

Answer 2

28х²+8х-7х-2=0
28х²+х-2=0
Д=1+4·28·2=√225
х=(-1+-15):56
Х₁=-1-15=-16:56=-0.2
Х₂=-1+15=14:56=0.25←Т.Е Х=0.25