5) -4.02 : (-1 1/2) = -4.02 : (-1.5) = 2.68
6) 2 2/5 : (-0.06) = 2.4 : (-0.06) = -40
Ответ буква (г!!Это правильно !!
4х²-(2х-1)²=15
4х² - 4х²+4х -1=15
4х=16
х=16:4
х=4
<span>(2 2\3x+1 3\7x)*21=58
(8/3х+8/7х)=58/21
56/21х+24/21х=58/21
80/21х=58/21
х=58/21*21/80
х=29/40=0.725</span>
(0.6x+0.8y)/(x+y+4)=0.56
(0.6x+0.8y)/(x+y+10)=0.5
0.6x+0.8y=(x+y+10)*0.5
0.6x+0.8y=0.5x+0.5y+5
0.6x-0.5x-0.8y-0.5y=5
0.1x+0.3y=5
0.1x=5-0.3y
x=(5-0.3y)/0.1
x=50-3y
(0.6*(50-3y)+0.8y) / ((50-3y)+y+4)=0.56
(3/5 * (50-3y)+0.8y) / (54-2y)=14/25
25*(3/5 *(50-3y)+4y/5)=14*(54-2y)
750-25y=14*(54-2y)
750-25y=756-28y
-25y+28y=756-750
3y=6
y=6/3
y=2
x=50-3*2
x=50-6
x=44
ответ:
60% раствор 44 кг
80% раствор 2 кг