Equations Question 3

For what real number $b$ , if any, will the equation $a-2b+ab=2$ be true for both $a=1$ and $a=-1$ ?

-2

-1

1

2

No such real number

b

exists.

Approach

a-2b+ab=2

a=1

(1)-2b+(1)b=2

1-2b+b = 2

-b = 1

b= -1

a=-1

(-1)-2b+(-1)b=2

-1-2b-b = 2

-3b=3

b= -1