Answers and Step-by-step explanations:
9-18.
a) All the angles of a triangle add up to 180, by definition. So, we can write the expression: 30 + 115 + x = 180.
Then, we can just solve for x by subtracting 30 and 115 from both sides:
x = 180 - 115 - 30 = 35 degrees
b) Again all three angles should add up to 180, so:
x + x + x = 180 ⇒ 3x = 180 ⇒ x = 180/3 = 60 degrees
9-19.
a) These angles add up to 180:
2x + x + 30 = 180 ⇒ 3x + 30 = 180 ⇒ 3x = 150 ⇒ x = 50
2x = 50 * 2 = 100
The missing angles are 100 degrees and 50 degrees.
b) Again, these add up to 180:
x + 10 + x + 90 = 180 ⇒ 2x + 100 = 180 ⇒ 2x = 80 ⇒ x = 40
x + 10 = 40 + 10 = 50
The missing angles are 50 degrees and 40 degrees.
Hope this helps!
ANSWER

EXPLANATION
The diagram represents the net of a rectangular prism.
The dimensions are,


and

The total surface area of a rectangular prism is given by:

We substitute the values to obtain,


the y intercept is the constant term on the x side
-6 * -2 which is 12
we can foil this out to see that
(x-6) (x-2)
x^2 -6x -2x+12
x^2 -8x+12
so the y intercept is (0,12)
Answer:
y = negative 2 x + 9
Step-by-step explanation: