# How do you evaluate f(x)=5x^4-8x^3+7x^2 at x=1 using direct substitution and synthetic division?

$f \left(1\right) = 4$
Using synthetic division wouldn't make sense here. When it asks you to evaluate $f \left(x\right)$ at $x = 1$, it's basically asking you for $f \left(1\right)$.
$f \left(1\right) = 5 \setminus \cdot {1}^{4} - 8 \setminus \cdot {1}^{3} + 7 \setminus \cdot {1}^{2} = 5 - 8 + 7 = 4$