2/3X + 5/9X = 11 2/3
6/9X + 5/9X = 35/3
11/9X = 105/9
11X = 105
X = 105/11 = 9 целых 6/11
<span>1)
</span>y=4x-7<span>
у=4*(-3)-7
у=-19
2)
</span>y=4x-7<span>
4х-7=9
4х=9+7
4х=16
х=4
3)
</span>y=4x-7<span>
С(2; 1)
1=4*2-7
1=1 проходит</span>
<span>cos2x - cos^2 x = -0.25
</span>cos^2 x - sin^2 x - cos^2 x =-0,25
- sin^2 x =- 0.25
sin x =0.5
x= 30 град
-m²+400=0
-m²=-400
m=√400
m=20