Answer:
The correct choice for a and b is 2 and 6 respectively.
Step-by-step explanation:
[tex]\frac{x^{2}+ax-4}{x+2}+\frac{x+b}{x+2}[/tex]
The least common multiple in the provided expression is x+2. Therefore, the above expression can be written as:
[tex]\frac{x^{2}+ax-4+x+b}{x+2}[/tex]
Arrange the like terms together as shown:
[tex]\frac{x^{2}+ax+x-4+b}{x+2}=\frac{x^{2}+x(a+1)+b-4}{x+2}[/tex]
It is given that after simplified her answer was x+1. Therefore, this information can be written as:
[tex]\frac{x^{2}+x(a+1)+b-4}{x+2}= x+1[/tex]
Multiply numerator and denominator by [tex]x+2[/tex] we get,
[tex]\frac{x^{2}+x(a+1)+b-4}{x+2}= \frac{(x+1)(x+2)}{x+2}[/tex]
Further simplify,
[tex]\frac{x^{2}+x(a+1)+b-4}{x+2}= \frac{(x^{2}+2x+x+2)}{x+2}[/tex]
Add the like terms:
[tex]\frac{x^{2}+x(a+1)+b-4}{x+2}= \frac{(x^{2}+3x+2)}{x+2}[/tex]
Now compare the coefficient of x term and constant term.
a+1=3 and b-4=2
further solve:
a=2 and b=6
Hence, the correct choice for a and b is 2 and 6 respectively.