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

Answer:

Option C.

Step-by-step explanation:

The given expression is ab - 2 = c

Option a : a = $\frac{c}{b}$ - 2

                 ab = c - 2b

                Not equivalent to the original expression.

Option b : b = c + $\frac{2}{a}$

                 ab = ac + 2 ⇒  $(\frac{ab-2}{a})$ = c

                Not equivalent

Option c  : ab = c + 2

                  ab - 2 = c

               Equivalent to original expression

Option d : a - $\frac{c}{2}$ = b

                 2a - c = 2b

                Not equivalent

Option e : b - $\frac{2}{c}$ = a

                 bc - 2 = ac ⇒ c (b-a) = 2 ⇒ c = $\frac{2}{b-a}$

                 Not equivalent

Option f : a = c + $\frac{2}{b}$

                ab = bc + 2

               $(\frac{ab-2}{b} )$ = c

              Not equivalent