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.
Answer:
<u><em>0.24 with a line over the 24. The line means that it is repeating.</em></u>
<em>Explanation,</em>
<em>There is not much to explain it's just simple divison.</em>
Step 1: multiple the second equation by 2 so that you get -1/4 for the coefficient of y, the same as in equation 1
equation 2 multiply by 2: 1/4 x - 1/4 y=38 ..........name this equation 3
subtract equation 1 from equation 3: (1/4 x -1/2 x)=38-10
-1/4 x = 28
x=-112
plug in x=-112 in any of the equation, you will get y=-264
so the answer is A
Answer: 5.32 × 10^12
Step-by-step explanation:
This is a question relating to indices. In indices, we add the power given for question relating to multiplication. Hence, this will be:
= (2.8•10^8)(1.9•10^4)
= (2.8 × 1.9) × 10^8+4
= 5.32 × 10^12
Therefore, the answer to the question will be 5.32 × 10^12.