Answer:
(r o g)(2) = 4
(q o r)(2) = 14
Step-by-step explanation:
Given
Solving (a): (r o q)(2)
In function:
(r o g)(x) = r(g(x))
So, first we calculate g(2)
Next, we calculate r(g(2))
Substitute 9 for g(2)in r(g(2))
r(q(2)) = r(9)
This gives:
{
Hence:
(r o g)(2) = 4
Solving (b): (q o r)(2)
So, first we calculate r(2)
Next, we calculate g(r(2))
Substitute 3 for r(2)in g(r(2))
g(r(2)) = g(3)
Hence:
(q o r)(2) = 14
Answer:
Solution given:
f(x)=x²
g(x)=x+5
h(x)=4x-6
now
23:
(fog)(x)=f(g(x))=f(x+5)=(x+5)²=x²+10x+25
24:
(gof)(x)=g(f(x))=g(x²)=x²+5
25:
(foh)(x)=f(h(x))=f(4x-6)=(4x-6)²=16x²-48x+36
26:
(hof)(x)=h(f(x))=h(x²)=4x²-6
27;
(goh)(x)=g(h(x))=g(4x-6)=4x-6+5=4x-1
28:
(hog)(x)=h(g(x))=h(x+5)=4(x+5)-6=4x+20-6=4x-14
Instead of typing it all on here, I included my explanations with the work.
Answer: Phone C
Using quick mental math, we can do 8% of 10 to get 0.8, which is close to the value of 0.0845*10. Also fairly quick is moving the decimal point over 1 spot to the right and we go from 0.0845 to 0.845 and that rounds to 0.8 when rounding to one decimal place. Recall that 8.45% = (8.45/100) = 0.0845
If you want to compute out the four results with a calculator, then it would look like this:
0.0845*20 = 1.69
0.0845*25 = 2.1125
0.0845*10 = 0.845
0.0845*18 = 1.521
and this shows that no other result (but choice C) is close to 0.8
So that's why the answer is choice C
