Given:
Consider the below figure attached with this question.
To find:
The measure of angle r by using the cosine rule.
Solution:
According to Law of Cosine,

Using the Law of Cosine, we get




On further simplification, we get






Therefore, the measure of angle r is 106.78 degrees.
It is -4!
1.8*-20=-36
32-36=-4
Answer
x=-2 and y=-3
Step-by-step explanation:
Step: Solvey=5x+7for y:
Step: Substitute5x+7 for y in 3x+y=−9:
3x+y=−9
3x+5x+7=−9
8x+7=−9(Simplify both sides of the equation)
8x+7+−7=−9+−7(Add -7 to both sides)
8x=−16
8x/8=−16/8
(Divide both sides by 8)
x=−2
Step: Substitute−2 for x in y=5x+7:
y=5x+7
y=(5)(−2)+7
y=−3(Simplify both sides of the equation)
Answer:
y = -2x + 5
Step-by-step explanation:
The slope is -2/1 and the y intercept is 5.