Commenter jdoe said it right: solve for y and leave the rest on the other side.
-x + 3y = 6
3y = 6 + x add x on both sides
3y = x + 6 rearrange to get the x first
y = (x + 6) /3 divide both sides by 3
y = x/3 + 6/3 split the numerator (caution - never split denominators)
y = x/3 + 2 simplify 6/3
Thus the line in slope intercept form of y = mx + b is y = 
ANSWER
Average Rate of Change
EXPLANATION
To find the average rate of change of y=f(x) from x=a to x=b means finding the slope of the secant line joining the points
(a,f(a)) and (b,f(b))
The slope of the secant line joining these points is
This gives the average rate of change of the function.
She added 64 grams which is 34 grams less than Wat was needed
She would make $98.50 in 10 hours.
Explanation :
255/20 = 12.75
12.75 - 2.90 = 9.85
9.85 x 10 = 98.50
Rounded to the nearest 1%, the cost exceeded the budget by 12%
