Use BEMDAS
(Brackets, Exponents, Multiplication and Division, Addition and Subtraction)
[tex]1.\\7+49:7=7+7=14\\2.\\30:5-3=6-3=3\\3.\\\dfrac{20+5}{5}-2=\dfrac{25}{5}-2=5-2=3\\4.\\(60-15):3^2=45:9=5\\5.\\\dfrac{5\times6+3}{10-7}=\dfrac{30+3}{3}=\dfrac{33}{3}=11[/tex]