Question

Select all of the following expressions that are equivalent to ab - 2 = c

a = c/b -2
b = c + 2/a
ab = c + 2
a - c/2 = b
b - 2/c = a
a = c + 2/b

Answer 1

The only one that's equivalent is The 3rd one. ab=c+2

Answer 2

Option C.

Explanation:

The given expression is ab - 2 = c

Option a : a =
`(c)/(b)` - 2

ab = c - 2b

Not equivalent to the original expression.

Option b : b = c +
`(2)/(a)`

ab = ac + 2 ⇒
`((ab-2)/(a))` = c

Not equivalent

Option c : ab = c + 2

ab - 2 = c

Equivalent to original expression

Option d : a -
`(c)/(2)` = b

2a - c = 2b

Not equivalent

Option e : b -
`(2)/(c)` = a

bc - 2 = ac ⇒ c (b-a) = 2 ⇒ c =
`(2)/(b-a)`

Not equivalent

Option f : a = c +
`(2)/(b)`

ab = bc + 2

`((ab-2)/(b) )` = c

Not equivalent