Mathematics: Need with these questions. show work to plzzzz

Need with these questions. show work to plzzzz

Ответ:

lace64

10.03.2022

$2.\\k(x)=2x^2-3\sqrt{x}\\\\k(9)\to\text{put the value of x = 9 to the equation of the function:}\\\\k(9)=2(9)^2-3\sqrt9=2(81)-3(3)=162-9=153\to\boxed{(4)}\\\\3.\\3(x^2+2x-3)-4(4x^2-7x+5)\qquad\text{use distributive property}\\\\=(3)(x^2)+(3)(2x)+(3)(-3)+(-4)(4x^2)+(-4)(-7x)+(-4)(5)\\\\=3x^2+6x-9-16x^2+28x-20\qquad\text{combine like terms}\\\\=(3x^2-16x^2)+(6x+28x)+(-9-20)\\\\=-13x^2+34x-29\to\boxed{(2)}$