6) Substitute x=-7-y into the first equation and solve for y. 2x+y=-4
x+y=-7

*y=-4
*y=10
*y=-17
*y=-10
*y=-8

please answer needed by 11:00pm

last option

step-by-step explanation:

given that δdef is right and isoceles,

assuming that side df is the hypotenuse means that de an ef are the other 2 sides that intersect at 90° and are of equal length.

because they are of equal length, we can say that they are congruent

because they intersect at 90°, their slopes must be opposite reciprocals.

only the last option satisfies these conditions.

98 points djdjsi zisksis sjsjsi sisksj sksjdj sksks sjsisj

-2

7 - 9 = -2

reversed:

-2 + 9 = 7