Beginners gebra 2: addition and subtraction
Rule: only like terms can add or subtract for example:
2a + 3a = 5a because 2a=a +a and 3a = a+a+a so plus them together gives a+a+a+a+a which simplifies into 5a
2a + 2b = 2a + 2b because they are unlike terms and cannot add
this also applies to subtraction
another rule is that the operating sign always belongs to the number to the right of it
2a + -3a = -1a since the 3a was negative
order of operations still apply so powers, brackets, multiplication & division then addition & subtraction but this question will only have addition and subtraction
also 2ab is the same as 2ba because they still mean the same thing
after learning this use this knowledge to solve the question below
what is -3acb + 2a --7abc +10a = ?
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lets seperate all the terms (-3acb) (+ 2a) (--7abc) (+10a)
now remember only like terms can add and subtract so lets break up the sum
sum 1 : (-3acb) (--7abc)
sum 2 : (+2a) (+10a)
sum 1 = 4abc because -- is double negative which equals a positive so it becomes -3abc + 7abc
sum 2 = 12a because both terms are positive and are adding
add both answers together which = 4abc + 12a