4×+7y=-12 __ -4x-y=-12 ________ 0x+6y=-24 , so you eleminated by it self 6y/6=-24/6 , you get : y=-4 and then you plug in 4x+7(-4)=-12 , that's your answer 4x-28 =-12 , you divided in both side 4x=-12+28 , 4x=16 , and then x=16/4 =4 , so x=4
It looks like you already have a common denominator (y^2-9). So, you can just add the two numerators and put that over the common denominator. Hope this helps!
Answer:

Step-by-step explanation:
We know that Sally picked 6 2/3 pounds of apples, which can be converted into an improper fraction: 20/3. Multiply 20/3 and 1/2. You will get 20/6, which is 3 1/3. Hope this helped :D
Answer: A. 31.5
Step-by-step explanation:
Using law of cosine because it is side angle side
a=16
b=21
angle = 116
c^2=a^2+b^2-2ab cosC, let C be the angle given
c^2=(21)^2+(16)^2-2(16)(21) cos(116)
c^2=441+256-672 cos(116)
i used a ti-89 and answered the right side and got
(you can find a ti-89 simulator online, but for problems like this make sure it is in degree mode)
991.585
c^2=991.585
take square root of both sides
=31.4894, which if you round it up it would be 31.5, so the answer would be A
therefore:
a=16
b=21
c=31.5