Answer:
-4x-5
Step-by-step explanation:
3+x-(x+2)-4x
3+x-x-2-4x
-4x-5
Answer:
The area of the triangle is of 21 units of area.
Step-by-step explanation:
The area of a triangle with three vertices
is given by the determinant of the following matrix:

In this question:
Vertices (3,0) (9,0) (7,6). So




The area of the triangle is of 21 units of area.
3(a+b) and 3a+b: not equivalent
4(x+2y) and 8y+4x: equivalent
6x^2 is the correct answer to the problem.