Hey there! I'm happy to help!
Let's call the number of weeks w. Since we want their balances, to be equal, we can create an equation.
1000-55w=800-30w
Now we solve for w. We add 30w to both sides.
1000-25w=800
Subtract 1000 from both sides.
-25w=-200
Divide both sides by -25.
w=8
Therefore, Mark and Patricia will have the same amount of money in their savings accounts after 8 weeks.
Have a wonderful day! :D
Hi.
An example of a fraction equivalence chain is this:

You can keep multiplying

by 2 to get a fraction chain.
Hope this helps!
Answer:
x is approximately 69.39 degrees.
Step-by-step explanation:
To find x in this triangle, we can use the sin rule:

The corresponding angle for each length is the one that lies directly opposite it. E.g. if 3.5 was our length 'a', then 55 degrees would be our angle A.
So let's take 3.5 and 55degrees as our length and Angle A, and 4 and x degrees as our length and angle B as we are trying to solve for x.
This would give us the following equation:

Since we are solving for an angle, it will be easier to rearrange the equation if we have it as the numerator, so we can flip the fractions to make it easier. It will still be equal as we are looking for the ratio.

From here let's isolate the sin(x) by multiplying by 4 and solving the values we have so far:

Now the final step is to use inverse sin to cancel the sin so we just have x:

x is approximately 69.39 degrees.
Hope this helped!