
Evaluate x^{2 }  1, when x = 5. 


Replace x with 5 and simplify. 


(5)^{2}  1 = 25  1 = 24 Answer 




Evaluate a^{2}b + a, when a = 3 and b = 2. 
Do NOT write:
3^{2}(2) + (3) as this is
9(2) + (3) = 21 



Parentheses are needed in this problem.



(3)^{2}(2) + (3) = 18 + (3) = 15 Answer 




Evaluate x^{3} + 3x^{2}  2x  5, when x = 4. 


Again, use parentheses to avoid errors. 


(4)^{3} + 3(4)^{2}  2(4)  5 = 64 + 48 + 8  5 = 13 Answer 






It may be the case that you will be asked to evaluate an expression using another expression.
Don't panic!!! Just follow the same process as you did when evaluating for a number.


Evaluate x^{2} + 2x  4, when x = 2a. 


Remember to use parentheses! 


(2a)^{2} + 2(2a)  4 = 4a^{2} + 4a  4 Answer 




Evaluate 3x + 10 when x = 3m + 15 


Remember to use parentheses! 


3(3m + 15) + 10 = 9m + 45 + 10 = 9m + 55 Answer 