Question

(-7ab+7a-1) - (ab+8)

Answer 1

Note 1: A constant number (A number without an exponent) will have the degree of 0. Always.Note 2: A variable without a visible exponent obtains an exponent of 1. Ex. x = Note 3: The operation sign before a coefficient/constant indicates if it's positive or negative. If no subtraction (or even addition) sign is in front of a value, it's positive. If a subtraction sign stands in front of a value, the value is negative. If an addition sign stands in front of the value, the value is negative.Note 4: When a number is not standing in front of a variable, it translates to 1 times that variable. Ex. x = 1xNote 5: coefficients contain a number and a variable.
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Step 1: Remove the parentheses. [we do this by distributing what's in the parentheses by 1. For the first part (-7ab + 7a-1), you can simply just remove the parentheses because it doesn't affect what's in the parentheses whatsoever. For the second one, (ab +8) however, you distribute -1 which gets us, essentially, different number signs. 

Result: $-7ab+7a-1 -ab - 8$

Step 2: Order, Sort, and Combine like terms.

View attachment!

Step 3: Solve.

$-7ab -ab = -7 - 1, ab = -8ab$
$+7a$
$-1 - 8 = -9$
Answer: $-8ab + 7a - 9$