Tell whether the two expressions are equivalent:

10a – 4a + 12;
6(a + 2)

10a- 4a= 6a        1) 6a+12
6xa= 6a   6x2=12    2) 6a+12

The expressions are equivalent. For the first sum, all you do is work out the total amount of a and what number is being added. However, on the second question, you have to expand the answer. I was taught a 'noddy method' to begin with. This should help.

Where is the expression you want us to evaluate?