Combining like terms would be defined as multiplying each term in a set of parentheses by the number outside of the parentheses.
The decimal .53 has the 3 in the hundredths place, so the fraction that this was originally is

. When you divide 53 by 100 on your calculator, you will get backk .53
Slope can be calculated using the formula: m= 
y1/x1 represents the first number in the bracket
y2/x2 represents the second number in the bracket
Calculation
m = 
m = 
m= 6/-12
m= -0.5 or -1/2
Therefore, the answer is B.