## Elementary Technical Mathematics

$-1\dfrac{3}{4}$
Make the fractions similar using their LCD of $12$: $=-\dfrac{2(4)}{3(4)}+\left(-\dfrac{5(2)}{6(2)}\right)-\dfrac{1(3)}{4(3)} \\=-\dfrac{8}{12} + \left(-\dfrac{10}{12}\right) - \dfrac{3}{12} \\=\dfrac{-8-10-3}{12} \\=-\dfrac{21}{12} \\=-1\dfrac{9}{12} \\=-1\dfrac{3}{4}$