First write out your equation with "x" in with the highest exponent in front:
-9x⁴+6x³+3x³-2x²
simplify by adding numbers with the same exponents together
-9x⁴+6x³+3x³-2x² =
-9x⁴+9x³-2x²
When x=1, it is important to know that 1 raised to any exponent will still always equal 1.
So, for your problem let's forget about the exponents and just plug in 1 for x.
-9x⁴+9x³-2x²
-9(1)+9(1)-2(1)=
-9+9-2=
-2
Answer:
-9x⁴+6x³+3x³-2x² is equal to (-2) when x=1
