<span>Answer:
The multiplication factor of increase should be inverse of the multiplication factor of decrease.
e.g. Say you have a number 100.
You increase it by 25%. The multiplication factor is 5/4 i.e. when you multiply 100 by 5/4, you get 100*5/4 = 125. This is 25% more than 100.
Now you want to decrease it by a certain % such that you get 100 back.
Basically, 100*5/4 * x = 100
So x = 4/5 (inverse of 5/4)
Hence, you decrease by 20% (the multiplication factor of 20% is 4/5)
or
Use this formula: cumulative % change = a + b + ab/100
You want the cumulative change to be 0.
a + b + ab/100 = 0
If you know that you are increasing by 25% and want to find the % by which you should decrease to get the same number,
25 + b + 25b/100 = 0
5b/4 = -25
b = -20
So you need to decrease (hence you get the -ve sign) by 20%.</span>
Solving <span>8x-5y=10 for y helps us to identify the y-intercept:
-5y = -8x + 10. Dividing both sides by -5, we get (8/5)x -2. Therefore, y = (8/5)x - 2; the y-intercept is (0,-2).
The equation </span><span>-6x-7y=-6 can be solved for its slope in the same manner.
7y = -6x + 6; then y = (-6/7)x + 6/7. Its slope is -7/6. A line perpendicular to this line has slope equal to the negative reciprocal of -7/6, which is 6/7.
So, using the slope-intercept form, y = mx + b becomes y = (6/7)x -2.</span>
52/4 = 13
$13 = 1 hour.
$6.50 = halfhour
13 x 3 = $39
She would have to work for 3 hours to earn $39
Answer:
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Step-by-step explanation:
A. because is $6 for every month as said in 6x, then an additional 12 for signing up, making 6x + 12 and she wants it to be under $60 so you use the less than sign making 6x+12 <60