Use PEMDAS
P Parentheses first
E Exponents (ie Powers and Square Roots, etc.)
MD Multiplication and Division (left-to-right)
AS Addition and Subtraction (left-to-right)
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[tex]\dfrac{3.5\times2+9}{10.4-1.4\times2}=\dfrac{7+9}{10.4-2.8}=\dfrac{16}{7.6}=\dfrac{16\cdot10}{7.6\cdot10}=\dfrac{160}{76}=\dfrac{160:4}{76:4}=\dfrac{40}{19}\\\\\dfrac{40}{19}=40:19\approx\boxed{2.11}[/tex]
