Answer:
(-5,5)
Step-by-step explanation:
Multiply the first equation by -2,and multiply the second equation by 1.
−2(x+5y=20)
1(2x−7y=−45)
Becomes:
−2x−10y=−40
2x−7y=−45
Add these equations to eliminate x:
−17y=−85
Then solve−17y=−85for y:
(Divide both sides by -17)
y=5
x+5y=20
Substitute 5 for y in x+5y=20:
x+(5)(5)=20
x+25=20(Simplify both sides of the equation)
x+25+−25=20+−25(Add -25 to both sides)
x=-5
Let x be the height of the box and y be the length of one side of the base then:-
V = xy^2 = 108
x = 108/y^2
Surface area = y^2 + 4xy
S = y^2 + 4y* 108/y^2
S = y^2 + 432/y
Finding the derivative:-
dS/dy = 2y - 432/y^2 = 0
2y^3 = 432
y^3 = 216
y = 6
Check if this gives a minimum value:-
second derivative = 2 + 864/y^3 which is positive so minimum.
V = xy^2 = 108
36y = 108
y = 3
Answer :- dimensions of the box is 3*6*6 metres
Answer:
D. increase
Step-by-step explanation
Intrest and fees are used to make process, and It increases the cost. You have to pay it back in the end.
Lateral Area = Surface Area - Area of Base.
<span> that'll be 55ft^2 - 25ft^2 = 30ft^2.</span>
41.4
Step-by-step explanation:
Hope this helps ∞<3
let me know if its right or wrong
