1. **State the problem:** Simplify each algebraic expression by combining like terms. 2. **Recall the rule:** Like terms have the same variable raised to the same power. Combine their coefficients by addition or subtraction. 3. **Simplify each expression:** - For $3a + 3a$: $$3a + 3a = (3 + 3)a = 6a$$ - For $-5m + m + 5$: Combine like terms with $m$: $$-5m + m = (-5 + 1)m = -4m$$ So the expression becomes: $$-4m + 5$$ - For $p + 3 + 4p + 5$: Combine like terms with $p$: $$p + 4p = (1 + 4)p = 5p$$ Combine constants: $$3 + 5 = 8$$ So the expression becomes: $$5p + 8$$ - For $a - 3b - 7a - 3$: Combine like terms with $a$: $$a - 7a = (1 - 7)a = -6a$$ The expression becomes: $$-6a - 3b - 3$$ 4. **Final answers:** - $6a$ - $-4m + 5$ - $5p + 8$ - $-6a - 3b - 3$