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.
I'm thinking this is what the problem looks like:

. The first thing to do is to move the

over to the other side because it has a common denominator with the other side. Doing that and at the same time combining them over their common denominator looks like this:

. The best way to solve for x now is to cross-multiply to get 3(4-x)=-4(x-4). Distributing through the parenthesis is 12 - 3x = -4x + 16. Solving for x gives us x = 4. Of course when we sub a 4 back in for x we get real problems, don't we? Dividing by zero breaks every rule in math that there ever was! So, yes, the solution is extraneous.
Answer:
12:44, or if simplified 3:11
Step-by-step explanation:
In mathematics, a ratio indicates how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8∶6, which is equivalent to the ratio 4∶3). Similarly, the ratio of lemons to oranges is 6∶8 (or 3∶4) and the ratio of oranges to the total amount of fruit is 8∶14 (or 4∶7).
The length would be 6 and the width would be 4 to get 24 as the area.