The required expressions are both equations 1 and 2 as shown:

.... 2
Complementary angles are angles that sum up to 90 degrees. For instance, and A and B are complementary if A + B = 90.
According to the question, if two complementary angles have measures of s and t then:

Twice of 's' is expressed as 
If t is less than twice s, this can be expressed as
.... 2
The required expressions are both equations 1 and 2 as shown:

.... 2
Learn more on word problems leading to simultaneous equations here: brainly.com/question/14294864
Using the model equation, the predicted mean score on the final given a score of <em>10 points above the class mean</em> in the mid term exam is 50.7
<u>The Least - Square Regression equation which models the relationship between midterm and final exam score is</u> :
x = 10 points ; <u>substitute the value of x = 10 into the regression equation</u> ;
γ=46.6 + 0.41(10)
γ=46.6 + 4.1
γ = 50.7
The <em>number of points above the mean</em> he'll score in the final exam is predicted to be 50.7
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Answer:
21
Step-by-step explanation:
Substitute.
We are given x = 3, y = 9 and z = 2
3(9-2) = 3(7) = 21