1/4(5-3х)+1/5(2х+7)=4 3/4
1/4(5-3x)+1/5(2x+7)=4 3/4
1,25-0,75x+0,4x+1,4= 4,75
-0,75+0,4x=2,1
-0,35x=2,1
x=-6
1/5-3x + 4/5(2x+7)= 12
1/5-3x + 4/5(2x+7) -12= 0
5(2x+7)+4(5-3x)-60(5-3x)(2x+7)/5(5-3x)(2x+7)=0
10x+35+20-12x-600x-2100+360^2+1260x/ 5(5-3)(2x+7)=0
658x-2045+360x^2=0
360x^2+658x-2045=0
x1/2= -329±√329^2+736200/360