Answer:
See explanation
Step-by-step explanation:
A. Let x represent the original test scores.
(1) The teacher will give a 10-point bonus, then the score will be x + 10. Hence,
[tex]f(x)=x+10[/tex]
(2) The teacher will increase everyone's grade by 9% of their score, then the score will be x + 0.09x = 1.09x. Hence,
[tex]g(x)=1.09x[/tex]
B. If [tex]f(x)=x+10[/tex] and [tex]g(x)=1.09x,[/tex] then
[tex]f(g(x))=g(x)+10=1.09x+10[/tex]
Meaning: the teacher increased by 9% the score and then increased the result by 10 points.
[tex]f(g(75))=1.09\cdot 75+10=91.75[/tex]
C. If [tex]f(x)=x+10[/tex] and [tex]g(x)=1.09x,[/tex] then
[tex]g(f(x))=1.09f(x)=1.09(x+10)[/tex]
Meaning: the teacher increased by 10 points the score and then increased the result by 9%.
[tex]g(f(75))=1.09(75+10)=92.65[/tex]
D. [tex]g(f(x))\neq f(g(x))[/tex] because [tex]1.09(x+10)\neq 1.09x+10[/tex]