First pic ; they are complementary angles , so C !!
second pic ; both angles are supplementary angles !! as sum is 180° !!
The marked angles are opposite angles, and as such they have the same measure. So, we have

Subtract 2a and 11 from both sides to get

Divide both sides by 4 to get

Now that we know the value of a, we can compute the measure of the angles. We can also verify that the solution we found is correct by verifying that both expressions actually give the same result:


So for this you just want to divide 4/5 by 9/10 because it is the opposite of the equation.
9/10 / 4/5
To divide fractions, you just multiply and reverse the second fraction.
For example:
9/10 * 5/4
Now you can just normally multiply.
45/40
Or, simplified,
9/8
(Or 1 1/8)
To solve this problem you need to figure out the volume of the sipping container, and the volume of the tissue box.
39*19.5*19.5=14,829.75
6.5*6.5*6.5=274.63
In order to figure out how many fits you need to divide
14,829.75/274.63=53.99
The maximum number that you can fit is the box is 53.
Hope this helps
1/4 of her original money is 1.25 + 1.60 = 2.85
She started with 2.85 * 4 = 11.40 pounds.