(2.61 -4х) /0,03 + 4.6 =90

(2.61-4х):0.03+4.6=90

(2.61-4х):0.3=90-4.6

(2.61-4х):0.03=85.4

2.61-4х=2.562

-4х=2.562-2.61

-4х=-0.048

х=-0.048:(-4)

х=0.012

ОТВЕТ:0.012

(2,61-4х):0,03+4,6=90

(2,61-4х):0,03=90-4,6

(2,61-4х):0,03=85,4

2,61-4х=85,4*0,03

2,61-4х=2,562

-4х=2,562-2,61

-4х=-0,048

х=-0,048:(-4)

х=0,012