(2n + 5k)^2 = (2n + 5k)(2n + 5k)
Here we need to use FOIL
First - 2n * 2n = 4n^2
Outside - 2n * 5k = 10nk
Inside - 5k * 2n = 10nk
Last - 5k * 5k = 25k^2
That gives us 4n^2 + 10nk + 10nk + 25k^2, we can combine 10nk + 10nk to give 20nk, and a final equaion of 4n^2 + 20nk + 25k^2
First solve the second equation to equal x.
x + y = 550
Subtract y from both sides.
x = 550 - y
Put this into the first equation in place of x.
3.75 (550 - y) + 4y = 2160
Multiply everything in the parenthesis by 3.75
2062.5 - 3.75y + 4y = 2160
Combine like terms.
2062.5 + 0.25y = 2160
Subtract 2062.5 from both sides.
0.25y = 97.5
Divide 0.25 on both sides.
y = 390
Put this into the second equation in place of y.
x + 390 = 550
Subtract 390 from both sides.
x = 160
So x = 160 and y = 390
Hope this helps!
We need more more.....
Stop playing dude like come on with that
Of multiplication or addition?
Answer:
4.87 ft
Step-by-step explanation:
The height of the skylight =
The height of the blue △ - the height of the red △
Let <em>b</em> ft be the height of the blue △.
sin 60° = 
<em>b</em> = 25 sin 60°
Let <em>r</em> ft be the height of the red △.
tan 40° = 
<em>r</em> = 20 tan 40°
The height of the skylight
= 25 sin 60° - 20 tan 40°
= 4.87 ft (rounded to the nearest hundredth)
