Solve.
{ 2d+e=8
{d-e-4
use the linear combination method.

there are infinitely many solutions.

there is no solution.

the solution is (4, 0).

the solution is (5, - 2).

The solution is (4, 0)

Step-by-step explanation:

Using Linear combination method to solve:

Since "e" have the same coefficient in both equation with opposite operator; we will add.

Divide both side by coefficient of d which is 3

Since d = 4; put 'd' into any of the equation to get 'e'

Therefore, the solution is (4, 0)

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

50

step-by-step explanation: