![-12x-35y=25\\ -8x-15y=-55\\ ](https://tex.z-dn.net/?f=-12x-35y%3D25%5C%5C%0A-8x-15y%3D-55%5C%5C%0A)
домножим первое уравнение на -2 ,а второе на 3 получим
![24x+70y=-50\\ -24x-45y=-165\\ \\ 70y-45y=-50-165\\ 25y=-215\\ y=-8.6\\ x=23](https://tex.z-dn.net/?f=24x%2B70y%3D-50%5C%5C%0A-24x-45y%3D-165%5C%5C%0A%5C%5C%0A70y-45y%3D-50-165%5C%5C%0A25y%3D-215%5C%5C%0Ay%3D-8.6%5C%5C%0Ax%3D23)
Ответ:
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<span>5sin3x - 9sin x = 0</span>
5(3sinx - 4sin^3 x) - 9sinx = 0
15sinx - 20sin^3 x - 9 sinx = 0
6sinx - 20sin^3 x = 0
2sinx (3 -10sin^2 x) = 0
a) 2sinx = 0
sinx = 0
x1= πn
б) 3 - 10sin^2 x = 0
10sin^2x = 3
sin^2x = 3/10
sinx = +-√(3/10)
sinx = √(3/10)
x2 = (-1)^n * arcsin(3/10)+πn
sinx = -√(3/10)
x3 = (-1)^(n+1) * arcsin(3/10)+πn
1)=x²-8x+16-(3+5x)(3+5x)=
=x²-8x+16-(3+5x)²=
=x²-8x+16-9+30x+25x²=
=26x²+28x+7
2)Начерти по двум точкам
(2;-3),(5;3)