Well, let's write it out, shall we? 6c2-5d+8 Now plug in the numbers. 6(5^2)2-5(4)+8 Now simplify using PEMDAS Parentheses Exponents Multiplication Division Addition and Subtraction (They go together go from left to right in the equation) 5^2= 5*5 = 25 6 * 25 = 150 150 * 2 = 300 5 * 4 = 20 Rewrite the equation. 150-20+8 Use PEMDAS again ( refer to the previous mentioning) 150 - 20 = 130 130 + 8 = 138