The denominator of the second fraction can be factored as (a-2)(2a-7), then it becomes doable. You cancel the (2a-7) factors, and are left with:

Do note that you have erased the fact that a≠0 and a≠7/2, so you should always mention that.
10^-8 would be .000000001 I believe lightning would be the correct answer because .00000001 is bigger than 10^-8 hope this is correct
D is under multiplication
Answer:
Step-by-step explanation:
Put the numbers in place of the corresponding letter and do the arithmetic.
y -10 = 8 -10 = -2
12 -z = 12 -(-12) = 24
3 -x = 3 -(-3) = 6
z -24 = -12 -24 = -36