7.8 should be it, i am so sorry if its wrong hope it helps if its correct!
The answer is a(n) = 6n - 2
Let’s says that x is the measure of the angle. X and it’s supplement are equal to 180. X and it’s complement are equal to 90. The supplement is s and the complement is c. S is times c which is the same as 3c.
3c + x = 180
C+x = 90
X = 90 - c
3c + 90 - c = 180
2c = 90
C = 45
The complement of. 45 degree angle is 45 degrees.
The angle is 45 degrees.
There will be eight marbles on the 9th line
Answer:
D
Step-by-step explanation:
Recall that the area of a triangle is given by:

In this case, the base is <em>x</em> and the height is <em>y</em>. Hence:

We can write the following ratios:

Solve for <em>x</em> and <em>y</em>:

Substitute:

And simplify. Hence:

In conclusion, our answer is D.