On a coordinate plane, a circle has a center at (1, negative 2) and a radius of 4 units. Which equation represents a circle with the same radius as the circle shown but with a center at (-1, 1)? (x – 1)2 + (y + 1)2 = 16 (x – 1)2 + (y + 1)2 = 4 (x + 1)2 + (y –1)2 = 4 (x + 1)2 + (y – 1)2 = 16

hello from mrbilldoesmath!

answer:

x - 3

discussion:

x^2 - 9 = (x-3) (x+3)   so

(x^2-9)/ (x + 3) = x-3

you,

mrb

-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

step-by-step explanation:

where is the question is there is a formula or is there not one

what chart am i supposed to follow?