1. **Problem statement:** Calculate $x^2$ for given values of $x$: 3, 2.4, -3, 5, and -10.5. 2. **Formula:** The square of a number $x$ is given by: $$x^2 = x \times x$$ 3. **Calculations:** - For $x=3$: $$3^2 = 3 \times 3 = 9$$ - For $x=2.4$: $$2.4^2 = 2.4 \times 2.4 = 5.76$$ - For $x=-3$: $$(-3)^2 = (-3) \times (-3) = 9$$ - For $x=5$: $$5^2 = 5 \times 5 = 25$$ - For $x=-10.5$: $$(-10.5)^2 = (-10.5) \times (-10.5) = 110.25$$ 4. **Explanation:** Squaring a number means multiplying it by itself. Negative numbers squared become positive because a negative times a negative is positive. **Final answers:** - $3^2 = 9$ - $2.4^2 = 5.76$ - $(-3)^2 = 9$ - $5^2 = 25$ - $(-10.5)^2 = 110.25$