B=24:100*A=0.24*A
B=C+7
C=16:100*A
B=0.24*A
C=0.16*A
B=C+7
B=0.24*A
C=0.16*A
0.24*A=7+0.16*A
B=0.24A
C=0.16A
A*(0.24-0.16)=7
0.08*A=7
B=0.24*A
C=0.16*A
A=87.5
B=0.24*87.5=21
C=0.16*A=14
ответ: B=21
Y ' = (5x^2 + 15x - 1) '
= 5(x^2)' + 15(x)' - (1)' =
= 5*2x + 15*1 - 0 =
= 10x + 15