Kx-4=x^2+3xkx-4-x^2-3x=0x^2+3x-kx+4=0x^2+(3-k)x+4=0нужна одна общая точка значит D=0D=(3-k)^2-4*4=(3-k)^2-4^2=(3-k-4)(3-k+4)=(-k-1)(-k+7)k=7 k=-1теперь подставляем. 7x-4=x^2+3x7x-4-x^2-3x=0x^2-4x+4=0D=0 x=2 7x-4=7*2-4=10 ответ (2.10)можно посторить график, а можно ситстемой решатьвот ситсемаy=kx-4y=x^2-3x значок системыkx-4=x^2-3xx^2-3x-kx+4=0 значок системыдорешиваем последнее уравнениеx^2-(3+k)x+4=0чтобы прямая и парабола имели одну общую точку, полученное уравнение (которое последнее во второй системе) должно иметть один корень, значи D=0D=(-(3+k))^2-4*4=(3+k)^2-4^2=(3+k-4)(3+k+4)=(k-1)(k+7)D=0, значит (k-1)(k+7)=0k^2+6k-7=0k1=7 k2=-1теперь подставляем k 1) 7x-4=x^2-3x x^2-10x+4=0 D1=25-4=21 x1,2=(5 + - корень из 21)2) -х-4=х^2-3х х^2-2x+4=0 D<0 корней нет
Writing. Task -1.Choose the correct item. Hey there Marisa! I’m sorry to hear you’ve been feeling down lately. Moving to a new city 1) ... be easy. I remember I went through something similar when I 2) ... move to a different area because of my new job. I do have a couple of suggestions that 3) ... help. You said that you’re finding it hard to make new friends at work. Well, I’m sure it 4) ... be easy for someone as friendly as you to make friends. It just takes a little time. So, you 5) ... to worry, you just 6) ... show a little patience! Also, since I know how much you love performing, you 7) ... join a local theatre group. You’ll get to meet a lots of new people who have the same interest as you. Who knows? There 8)... be people from work there, too. This would give you the chance to get to know some of your colleagues better. Anyway, I’m absolutely certain that it’s only a matter of time before you settle in. By
