When we evaluate algebraic equations we substitute the variables with real numbers. When you know the value of the variables within the equation it becomes easier to find the correct answer that you are seeking.
For example: If you have an equation like w + c when W = 8 and C = 9 you would replace the variables w and c with 8 and 9. You would then end up with 8 + 9 simple enough when you are just learning about algebra.
Another example would be 5xz if you put the numbers 8 and 9 into the equation you would end up with 5(8)(9); so in order to evaluate this equation you would first multiply 5 and 8 to get 40 then you would multiply 40 and 9 to come up with your final answer of 360.
Now, if y = 8 and t = 6 in the following equations what do you think the answer would be?
in y – t
By putting your numbers into the equation y – t you should come up with the equation 8 – 6 = 2; and in 8yt you should come up with 8(8)(6) = 64(6) = 384 you are just multiplying each of the numbers to come up with the end result.
Evaluating algebraic expressions is an easy concept to learn once you understand the variables, and insert the real numbers into your equation.
Here are some to evaluate
If a = 5, t = 7, c = 6, and d = 3
1. 6a + 9t
2. 8c + 6d
3. a3 + 7t
4. 8(a + d)
5. 15(c + a)