Slope intercept: y = mx + b
Subtract 8x
-4y = 20 - 8x
Divide by -4
Y = -5 + 2x
Switch around
Solution: y = 2x - 5
If you decrease something by 4 percent,
you are keeping (100% - 4%) or 96% of the original
so multiply by the original amount by 96 percent or .96
If you have 100 pennies, and you give 4 away ( 4 percent decrease), you still have 96 pennies. You are keeping 96 percent of what you started with. This works no matter how much you start with.
Example:
you have 40 dollars
4% decrease
40 * .04 = 1.6 take this away
40 - 1.6 = 38.4 left
you keep 96 percent
40 * .96 = 38.4 left
Here is the answer with explanation
To find the circumference, you will use the formula for finding circumference of a circle.
I used the true value of pi for the calculations.
C = pi x d
pi x 27.13
C = 85.77mm
Not sure how simplified you need it...
8ab-3b+8