4–6х+15=10х+11
–6х–10х=11–15–4
–16х=–8
х=0,5
1) 4/15 : 2/25 = ( 4 х 25 ) / ( 15 х 2 ) = 100 / 30 = 10/3
2) 2/3 + 10/3 = 12/3 = 4
ответ 4
(6+x)*x=27
x^2+6x-27=0
D=36+108=12^2
x1=-6-12/2=-9
x2=-6+12/2=3
y1=-3
y2=9
7,2-3,3m=2.7m+3,2
7,2-3,2=2.7m+3,3m
4=6m
m=4/6
<span>m=2/3</span>