\(6x^2+2-4x=6x^2-4x+2.\)
\(-3+5x^2-2x=5x^2-2x-3.\)
\(a.Tính\) \(H\left(x\right)=M\left(x\right)+N\left(x\right)-P\left(x\right)\)
\(H\left(x\right)=\left(2x^2+5x-6\right)+\left(6x^2-4x+2\right)-\left(5x^2-2x-3\right)\)
\(------------------------\)
\(H\left(x\right)=3x^2+3x-1.\)
\(b.Tính\) \(GT\) \(của\) \(H\left(x\right)\) \(tại\) \(x=\dfrac{1}{3}.\)
\(H\left(\dfrac{1}{3}\right)=3\cdot\dfrac{1}{3}^2+3\cdot\dfrac{1}{3}-1=3\cdot\dfrac{1}{9}+3\cdot\dfrac{1}{9}-1\)
\(=\dfrac{1}{3}+1-1=\dfrac{1}{3}.\)
\(c.ChoQ\left(x\right)=3x^2+5x-2.Tìm\) \(K\left(x\right)=H\left(x\right)-Q\left(x\right)\)
\(H\left(x\right)-Q\left(x\right)=\left(3x^2+3x-1\right)-\left(3x^2+5x-2\right)\)
\(------------------------\)
\(K\left(x\right)=H\left(x\right)-Q\left(x\right)=-2x+1.\)
\(d.Tìm\) \(nghiệm\) \(K\left(x\right)\)
\(-2x+1\)
\(-2x+1=0\)
\(-2x=0-1\)
\(-2x=-1\)
\(x=-1:\left(-2\right)\)
\(x=\dfrac{1}{2}.\)
\(Vậy...\)
Mọi người giúp mình với ạ mình cần gấp!!!!!
