Answer:
74.30
Step-by-step explanation:
Let s = entry price for a student
Let t = entry price for a teacher
4s +5t = 95
6s+10t = 173
I will use elimination to solve this problem.
Multiply the first equation by -2
-2(4s +5t) = -2*95
Distribute
-8s - 10t = -190
Add this equation to the second equation to eliminate t
-8s - 10t = -190
6s+10t = 173
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-2s = -17
Divide by -2
-2s/-2 = -17/-2
s = 8.50
Now we need to find t
4s +5t = 95
Substitute s=8.50
4(8.50) +5(t) = 95
34 +5t = 95
Subtract 34 from each side
34-34 +5t = 95-34
5t = 61
Divide by 5
5t/5 = 61/5
t = 12.20
We want to find the cost for 3 students and 4 teachers
3s+4t
3(8.50) + 4(12.20)
25.50 + 48.80
74.30
Uhm I’m not sure, haven’t did fraction math in a long time
Answer: Choice D. 
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Work Shown:
We multiply the coefficients 9.2 and 7 to get 64.4, which is the same as 6.44*10^1 in scientific notation. When multiplying exponential expressions with the same base, we add the exponents
This is what the steps could look like

The final result is in scientific notation as the coefficient c is restricted such that 
Answer:
Step-by-step explanation:
X=9