Y = arccos (x)
D(y) = [ - 1; 1]
E(y) = [ 0; pi]
y = arccos (5x)
D(y) = [ - 1/5; 1/5]
E(y) = [ 0; pi]
y = arccos ( - 5x)
D(y) = [ - 1/5; 1/5]
E(y) = [ 0; pi]
y = arccos (4 - 5x)
D(y) = [ 3/5; 1]
E(y) = [ 0; pi]
y = 0,5*arccos (4 - 5x)
D(y) = [ 3/5; 1]
E(y) = [ 0; pi/2]
y = 0,5*arccos (4 - 5x) - 2
D(y) = [ 3/5; 1]
E(y) = [ - 2; pi/2 - 2]
10%=10/100=0,1
12%=12/100=0,12
0,1*4x+0,12*x=0,4*x=0,12*x=0,52*x
0,52*100%=52%
Итак, концентрация полученного раствора составляет 52%
13(5x-1)-15(4x+2)<0
65-13-60x-30<0
5x-43<0
5x<43
x<43\5
x<8,6