Answer:

Step-by-step explanation:
![\sf (3y-1)^2 -(2y+4)^2+(2y-3)(2y+3)\\\\Using \ formula:\\\\1) (a-b)^2 = a^2-2ab+b^2\\\\2) (a+b)^2= a^2+2ab+b^2\\\\3) (a+b)(a-b) = a^2-b^2\\\\Applying \ Formulas\\\\(3y)^2-2(3y)(1)+(1)^2-[(2y)^2+2(2y)(4)+(4)^2]+(2y)^2-(3)^2\\\\9y^2-6y+1-[4y^2+16y+16]+4y^2-9\\\\9y^2-6y+1 -4y^2-16y-16+4y^2-9\\\\Combining \ like \ terms\\\\9y^2-4y^2+4y^2-6y-16y+1-16-9\\\\9y^2 -22y-24\\\\\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Csf%20%283y-1%29%5E2%20-%282y%2B4%29%5E2%2B%282y-3%29%282y%2B3%29%5C%5C%5C%5CUsing%20%5C%20formula%3A%5C%5C%5C%5C1%29%20%28a-b%29%5E2%20%3D%20a%5E2-2ab%2Bb%5E2%5C%5C%5C%5C2%29%20%28a%2Bb%29%5E2%3D%20a%5E2%2B2ab%2Bb%5E2%5C%5C%5C%5C3%29%20%28a%2Bb%29%28a-b%29%20%3D%20a%5E2-b%5E2%5C%5C%5C%5CApplying%20%5C%20Formulas%5C%5C%5C%5C%283y%29%5E2-2%283y%29%281%29%2B%281%29%5E2-%5B%282y%29%5E2%2B2%282y%29%284%29%2B%284%29%5E2%5D%2B%282y%29%5E2-%283%29%5E2%5C%5C%5C%5C9y%5E2-6y%2B1-%5B4y%5E2%2B16y%2B16%5D%2B4y%5E2-9%5C%5C%5C%5C9y%5E2-6y%2B1%20-4y%5E2-16y-16%2B4y%5E2-9%5C%5C%5C%5CCombining%20%5C%20like%20%5C%20terms%5C%5C%5C%5C9y%5E2-4y%5E2%2B4y%5E2-6y-16y%2B1-16-9%5C%5C%5C%5C9y%5E2%20-22y-24%5C%5C%5C%5C%5Crule%5B225%5D%7B225%7D%7B2%7D)
Hope this helped!
<h3>~AH1807</h3>
Answer:
178cm
Step-by-step explanation:
x=180
y=160
0.4(x+y)+42 =
0.4(180 + 160) +42 =
0.4(340)+42=
136+42=
178cm
Answer: 14.5
i could be wrong if i am so sorry
It is C.
If you type in your calculator "Y=" and then " -4(2)^x " and click "GRAPH" you will see a descending graph, from left to right, that looks EXACTLY like the third graph in option C.
The answer to this question is 5a^2-6a+20+(-175a+102)over(5a^2+6a-9)