Answer:
15x - y = - 6.....15x + 6 = y...so we sub in 15x + 6 in for y on the other equation
5x - 3y = -13
5x - 3(15x + 6) = -13 <== the new equation
Step-by-step explanation:
Alright,
you will need to solve for each variable to find if they got the equation correctly or not..
Let's start with h
isolate h
(1/2)h = A/(b1+b2)
Now we need to get rid of 1/2 we may do so by multiplying both sides by 2
h = 2(A/(b1+b2))
And that's not how they did it for h so Option D doesn't apply
Let's see C
Also doesn't apply since they multiplied 2 only by A rather than A/h
Let's see B
Also not correct they made the same mistake as with option C
Let's see A
again same mistake
when multiplying both sides by 2
the 2 should be as following

I believe you should contact your instructor and explain that non of the options is right.
Answer: 75 cm per hour
Step-by-step explanation:
375 divided by 5=75
Answer:
c
Step-by-step explanation:
7^5 means that there are 5 7s eg 2^4 would be 2×2×2×2
Since 1 pound is $3.09, 4.5 pounds will be:

It says to round to nearest hundredth, so your answer is $13.91.