Answer:

Step-by-step explanation:
Notice that you are given an isosceles right-angle triangle to solve, since each of its two acute angles measures
. Then such means that the sides opposite to these acute angles (the so called "legs" of this right angle triangle) must also be of the same length (x).
We can then use the Pythagorean theorem that relates the square of the hypotenuse to the addition of the squares of the triangles legs:

We use just the positive root, since we are looking for an actual length. then, the requested side is:

Answer:
Sandra need to score at least <u>56%</u> in her fifth test so that her average is 80%.
Step-by-step explanation:
Given:
First 4 test scores = 87%, 92%, 76%,89%
Average targeted = 80%
We need to find the minimum score she needs to make on fifth test to achieve average of at least 80%.
Solution:
Let the minimum score she needs to make in fifth test be 'x'.
Total number of test = 5
Now we know that;
Average is equal to sum of all the scores in the test divided by number of test.
framing in equation form we get;

Multiplying both side by 5 we get;

Subtracting both side by 344 we get;

Hence Sandra need to score at least <u>56%</u> in her fifth test so that her average is 80%.
Expand the brackets first
5(wx-v) = 9(x + v)
5wx - 5v = 9x + 9v
Get all x's on one side and everything on on the other side
9x - 5wx = 9v + 5v
factorise out the x
x(9-5w) = 14v
then divide by 9-5w
x = 14v/(9-5w)
The last one is correct because 60+35+35+35=165
55+55+55=165