=12√2cos225=12√2cos(180+45)=12√2(-cos45)= -12√2 *<span>√2/2= -12</span>
Y^2-7y+10=0
Д=49-4*1*10=49-40=9 (3)
y1=7+3/2=10/2=5
y2=7-3/2=4/2=2
ответ: 5, 2
15х-4у=8
-3х+у=1
у=1+3х
15х-4*(1+3х)=8
15х-4-12х=8
3х=8+4
3х=12
х=4
у=1+3*4=13
3*(2-Y) - 2Y - 11 = 0
6 - 3Y - 2Y - 11 = 0
- 5Y - 5 = 0 ---> Y = ( - 1)
X = 2 -(-1) = 2 + 1 = 3
Ответ: Х = 3 ; Y = ( - 1 )