Jen factored x² - 4x - 21 as (x - 3)(x + 7) What did she do wrong?

She didn't put the sign's in the proper place, it should be ( x + 3 ) ( x - 7 )

Step-by-step explanation:

( x - 3 ) ( x + 7 ) = x² + 7x - 3x - 21 = x² + 4x - 21

( x + 3 ) ( x - 7 ) = x² - 7x + 3x - 21 = x² - 4x - 21

-3

step-by-step explanation:

a drawing really does here:

so i draw the horizontal line y=2 and the vertical line x=-2 at this intersection i put b (this is where my right angle is going to be).   so point b is at (-2,2).   point a is 5 units long and is also on y=2 so this point has to be (3,2) or (-7,2) -doesn't matter i will go with (3,2).

now we know c is at (-2,y) we don't know the y yet bet we know that c is on x=-2.

we have the area of the triangle is .5bh=12.5

we know the base length is 5 (ab)

we have the height is (2-y) if you look at your

plug in

.5(5)(2-y)=12.5

solve for y to get the y-coordinate for c

2.5(2-y)=12.5

divide both sides by 2.5 giving:

2-y=5

now subtract 2 on both sides

-y=3

y=-3

10.4 inches

step-by-step explanation:

2x2x2.6