Ta có :
P(x) = \(x^2+\left(x+2\right)^2+...+\left(x+98\right)^2-\left[\left(x+1\right)^2+\left(x+3\right)^2+...+\left(x+99\right)^2\right]\)
P(x) = \(\left[x^2-\left(x+1\right)^2\right]+\left[\left(x+2\right)^2-\left(x+3\right)^2\right]+...+\left[\left(x+98\right)^2-\left(x+99\right)^2\right]\)
P(x) = \(\left(x^2-x^2-2x-1\right)+\left(x^2+4x+4-x^2-6x-9\right)+...+\left(x^2+196x+9604-x^2-198x-9801\right)\)
P(x) = \(\left(-2x-1\right)+\left(-2x-5\right)+...+\left(-2x-197\right)\)
P(x) = \(-\left(2x+2x+2x+...+2x\right)-\left(1+5+...+197\right)\)
P(x) = \(-2x\times50-\dfrac{\left(197+1\right)\times50}{2}\)
P(x) = \(-100x-4950\)
Suy ra a = -100 và b = -4950
Do đó a - b = 4850
ố hố.Bạn liều wá.Chỗ mk coi thi căng lắm ak