pakai caranya biar paham:)

6x² + 8x - 5
6/(2+1) x^(2+1) + 8/(1+1) x^(1+1) - 5x
2x³ + 4x² - 5x masukan interval 3 dan 1

2(3)³+4(3)²-5(3) - {2(1)³+4(1)²-5(1)}
54+36-15 - {2+4-5}
75 - 1
= 74