Answer:
147
Step-by-step explanation:
x = 7,
3x² = 3 × 7²
= 3 × 49
= 147
7/8 there you go the right answer xD
Answer:
You want to solve for x, the first thing you need to do is distribute
The 2 through the x+4 then the other 2 through the -8-x
2(x+4)= 2x+8
2(-8-x)= -16-2x
2x+8=-16-2x-2x (combine like terms on the right side)
2x+8=-16-4x (now subtract 8 from each side)
2x=-24-4x (8-8=0, -16-8=-24) (now add 4x to each side)
6x=-24 (-4x+4x=0, 2x+4x=6x), (divide each side by 6)
x=-4 (6/6=1, -24/6=-4)
x=-4
Hope this helps ;)
Intersection of the first two lines:

Multiply the first equation by 4 and the second by 5:

Subtract the two equations:

Plug this value for y in one of the equation, for example the first:

So, the first point of intersection is 
We can find the intersection of the other two lines in the same way: we start with

Use the fact that x and y are the same to rewrite the second equation as

And since x and y are the same, the second point is 
So, we're looking for a line passing through
and
. We may use the formula to find the equation of a line knowing two of its points, but in this case it is very clear that both points have the same coordinates, so the line must be 
In the attached figure, line
is light green, line
is dark green, and their intersection is point A.
Simiarly, line
is red, line
is orange, and their intersection is B.
As you can see, the line connecting A and B is the red line itself.
D. 90 im pretty sure its this. hope this helped :)