Changing from negative to positive
9a + (9t+27)=x
To write it another way you could flip the numbers around:
(9t+27)+9a=x
Or flip the variable to the other side.
x=9a + (9t+27)
Any way you put the numbers as long as x is on the either side, you will get the same answer.
Hope this helps!
60 + 90
GCF = 30
(30 * 2) + (30 * 3) = 30(2 + 3) <== the correct way
The mistake Axial made was he did not pick the greatest common factor...he picked 3 instead of 30.