2(5n-2)=4(n+2)
10n-4=4n+8
6n-4=8
6n=12
n=2
Question 1
The given system of equations is:

Equate the two equations:

Rewrite in standard form:




When we put x=0, in y=3x +6, we get:

One solution is (0,6)
When we put x=-2, into y=3x+6, we get:

Another solution is (-2,0)
The solutions are; (0,6) and (-2,0)
Question 2:
The function is

Let us put x=-x,

This gives:

We can observe that:

This is the property of an even function.
Question 3:
The given function is

The average rate of change of f(x) from x=a to x=b is given as:

This is the slope of the secant line connecting the two points on f(x)
From x=2 to x=6, the average rate of change

The average rate of change is 11
The zeroes (where the line crosses the x-axis, these are also the solutions) and the vertex (the highest or lowest point)
You would form this inequality:
52 + 2x < (or equal to) 180
Then, solve as you would in an ordinary equation.
Subtract 52 from both sides of the sign. 180 - 52 = 128.
So, 2x is less than or equal to 128.
Divide 128 into two to get 64.
The height of the frame must be 64 inches.