<span>Point A with coordinates (x,y) rotated 180 degrees around O gives point A' with coordinates (-x,-y).
Hope this helps :D
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Answer:
Step-by-step explanation:
-9x^3(x^2 - 4x - 21) =
-9x(x - 7)(x + 3) <===
Step-by-step explanation:
step 1. let l be the length of the rectangle
step 2. l = 2x + 4
step 3. lx = 390 yd^2
step 4. (2x + 4)x = 390
step 5. 2x^2 +4x = 390
step 6. 2x^2 + 4x - 390 = 0
step 7. -4 +- sqr(4^2 -4(2)(-390))/2(2) quadratic formula
step 8. (-4 +- sqr(3136))/4
step 9. (-4 +- 56)/4
step 10. x = 13yd, l = 2x + 4 = 2(13) + 4 = 30yd.