Question

Rearrange the formula S = a (a - r) forr. A) r = a(S - 1) B) r = (S - 1) a C) r = a(S - 1) S D) r = a(S + 1) S

Answer 1

Answer: C) $r=a(\dfrac{S-1}{S})$

Step-by-step explanation:

The given formula : $S=\dfrac{a}{(a-r)}$

To rearrange the formula to find the formula for r , first we multiply both sides with (a-r), we get

$(a-r)S=a$

Divide both sides by S , we get

$a-r=\dfrac{a}{S}$

Subtract a on both sides , we get

$-r=\dfrac{a}{S}-a\\\\ -r=a(\dfrac{1}{S}-1)$

Multiplying (-1) on both sides , we get

$r=-a(\dfrac{1}{S}-1)\\\\ r=a(1-\dfrac{1}{S})\\\\ r=a(\dfrac{S-1}{S})$

Hence, the correct answer is : C) $r=a(\dfrac{S-1}{S})$

Answer 2

Answer: C) r =  a(S - 1) /S

Step-by-step explanation: