Question

Tell whether the two expressions are equivalent: 10a – 4a + 12; 6(a + 2)

Answer 1

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.

Answer 2

10a-4a+12 6a = -12 a= -2 6(a+2) 6a + 12 6a = -12 a = -2