Use mathematical sindution to proste that, \( 1^{2}+3^{2}+5^{2}+\ldots+(2 n+1)^{2}=\frac{(n+1)(2 n+1)(2 n+1)}{3} \) Where \( n \) is positive sinteger.

Use the distributive property to fill in the blanks below. \[ 7 \times(9+5)=(7 \times \square)+(7 \times \square) \]

Which operation should you do first? \( \begin{array}{llll}\text { 3. } 6-2 \times 2 & \text { 4. } 33-(4+6) & 5.6 \times(2-5) & 6.7+4 \times 3\end{array} \)

Which term of the sequence \( \frac{1}{4} ;-1 ;-2 \frac{1}{4} ; \ldots \) is equal to \( -13 \frac{1}{2} ? \)

(1) \( 3: 5=30: ? \)

Express \( 2 . \dot{8} \dot{3} \) as a fraction leaving it in the form \( \frac{\mathrm{p}}{\mathrm{q}} \)