<p>Quantum algorithms for optimization often achieve speedups in the&nbsp;problem dimension.&nbsp;Yet their&nbsp;&nbsp;error dependence and sensitivity&nbsp;to&nbsp;scale makes it&nbsp;challenging&nbsp;to&nbsp;identify broad classes of&nbsp;optimization&nbsp;problems for which thei r&nbsp;is a&nbsp;clear advantage over classical&nbsp;algorithms.&nbsp;This&nbsp;</p><p>dissertation is comprisedof multiple projects spanning three parts that seek to reducethis gap.&nbsp;Part I concerns quantum linear algebra. We provide a construction for implementing matrix&nbsp;arithmetic operations&nbsp;such as&nbsp;Kronecker&nbsp;and Hadamard&nbsp;products on a quantum&nbsp;computer. Then&nbsp;</p><p>we demonstrate how Iterat ive Refinement can be leveraged&nbsp;to exponentialy improve the dependence&nbsp;on precision&nbsp;in&nbsp;the&nbsp;overall running time associated&nbsp;with classicaly solving linear systems of equations using quantum computers.</p><p><br></p>