X + 4y = -9 . . . (1)
2x + 5y = -6 . . . (2)
From (1): x = -9 - 4y . . . (3)
Substituting (3) into (2) gives, 2(-9 - 4y) + 5y = -6
-18 - 8y + 5y = -6
Required equation is -18 - 3y = -6
Answer:
21.75 m x 21.75 m
Step-by-step explanation:
87 m of fencing
perimeter: ![2l+2w=87](https://tex.z-dn.net/?f=2l%2B2w%3D87)
⇒ ![l=\frac{87-2w}{2}](https://tex.z-dn.net/?f=l%3D%5Cfrac%7B87-2w%7D%7B2%7D%20)
area ![A=wl](https://tex.z-dn.net/?f=A%3Dwl)
⇒ ![A=w(\frac{87-2w}{2} )=\frac{87}{2} w-w^2](https://tex.z-dn.net/?f=A%3Dw%28%5Cfrac%7B87-2w%7D%7B2%7D%20%29%3D%5Cfrac%7B87%7D%7B2%7D%20w-w%5E2)
Max area when ![\frac{dA}{dw} =0](https://tex.z-dn.net/?f=%5Cfrac%7BdA%7D%7Bdw%7D%20%3D0)
⇒ ![w=21.75](https://tex.z-dn.net/?f=w%3D21.75)
Therefore,
⇒ ![l=21.75](https://tex.z-dn.net/?f=l%3D21.75)
So the dimensions are L = 21.75 and W = 21.75
I know that this is a square, but all squares are technically rectangles.
Answer:
$ 825
Step-by-step explanation:
10 yard = $150
55yard = ?
55yard* $150 /10yard
55*15 =825 then the correct answer of
$55 yard is 825