Answer
$x^2$
Work Step by Step
To find the GCF, factor each number. The product of the common factors is the greatest common factor.
$x^3=\underline x\times \underline x\times x$
$x^2=\underline x\times \underline x$
$x^{10}=\underline x\times \underline x\times x \times x\times x \times x\times x \times x\times x \times x$
$GCF=x\times x=x^2$