Answer:
Stock A
Stock B
Step-by-step explanation:
When we say something is increased (or decreased) by a percentage, we mean that the percentage of the original amount is added to (or subtracted from) the original amount.
Of course, you know that 5% = 5/100 = 0.05, so that an increase of 5% in d would be ...
d + 0.05d . . . . . 5% of the original amount (d), added to d
Factoring out d gives another version of this expression:
d(1 +0.05)
and combining the numbers gives yet another version of the same expression:
1.05d
These are the ways that the increase in Stock A can be expressed:
d +0.05d
d(1 +0.05)
1.05d
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Similarly, if the "increase" is negative, as for Stock B, we can use the same sorts of expressions. +0.05 gets replaced by -0.05, but the form of the expression is the same.
d - 0.05d . . . . . the original amount decreased by 5%
d(1 -0.05) . . . . .d factored out
0.95d . . . . . . . . the numerical coefficient simplified
) times bigger than twice the radius. Mathematically, this can be writted as 
, where C equals the circumference and r equals the radius, or 
where C equals the circumference and d equals the radius.