Answer:
& 
Step-by-step explanation:
I'm sure you are familiar with the product rule,
If y = u*v => dy/dx = u * dv/dx + v * dy/dx <----- product rule
In this case:

Now remember the sum rule:

For this second bit we apply the chain rule:

If we substitute these values back into the expression...
...we get the following:

The rest is just pure simplification:

Now let's equate this to equal 8 for the second bit and solve for x:

Answer:
2b+t/2=a
Step-by-step explanation:
3a + 4b = 5a-t
-3a -3a
4b = 2a - t
+t +t
4b + t = 2a
/2 /2
2b+t/2=a
Answer:
I think the answer is D because it doesn't show that the bottom lengths are the same.
Step-by-step explanation: