nilai dari f(x)=(3x+1)(2-3x)=

[tex](3x + 1)(2 - 3x)[/tex]
caranya disubtitsikan

[tex] = 6x - 9 {x}^{2} + 2 + 3x \\ = - 9 {x}^{2} + 9x + 2 \\ = 9 {x}^{2} - 9x - 2[/tex]

semoga membantu

f(x)=(3x+1)(2-3x)

Cara subtitusi yang benar:
= (3x+1)(-3x+2)
= 3x (-3x+2) +1 (-3x+2)
= -9x² + 6x - 3x + 2
= -9x² + 3x + 2
= 9x² - 3x - 2