The easiest way to solve this is by elimination.
3x - y = 6
6x + y = 21
Since you have a negative and positive y with the same coefficients (1), they cancel, and you add the other terms so it would look like:
9x = 27
Then solving for x leaves you with x = 3
Then you take the x value of three and plug it into to either of the equations, so
3(3) - y = 6
9 - y = 6
subtracting 9
-y = -3
then dividing by -1
y = 3
so the solution is x = 3 y = 3 or (3,3)
448 square inches.
The surface area of the box is 448 square inches so that is the least amount of paper needed to cover the box.
Answer:
V = 277.088 m³
Step-by-step explanation:
Volume of Cylinder Formula: V = πr²h
We are given <em>r</em> = 4.2 and <em>h</em> = 5, so simply plug it into the formula and solve:
V = π(4.2)²(5)
V = 17.64π(5)
V = 88.2π
V = 277.088
We know that
cos a+cos b=cos[(a+b)/2]*cos[(a-b)/2]
we have
<span>cos(π/7)+cos(2π/7)+cos(3π/7)+cos(4π/7)-------------> equation 1
</span>cos(4π/7)+cos(2π/7)=cos[(4π/7+2π/7)/2]*cos[(4π/7-2π/7)/2]
=cos(3π/7)*cos(π/7)
then
cos(4π/7)+cos(2π/7)=cos(3π/7)*cos(π/7)--------------> equation 2
[cos(3π/7)+cos(π/7)]=cos[(3π/7+π/7)/2]*cos[(3π/7-π/7)/2]
=cos(2π/7)*cos(π/7)
then
[cos(3π/7)+cos(π/7)]=cos(2π/7)*cos(π/7)-----------> equation 3
I substitute 2 and 3 in 1
[cos(3π/7)+cos(π/7)]+[cos(4π/7)+cos(2π/7)]
{cos(2π/7)*cos(π/7}+{cos(3π/7)*cos(π/7)}
=cos(π/7)*[cos(2π/7)+cos(3π/7)]
the answer is
cos(π/7)+cos(2π/7)+cos(3π/7)+cos(4π/7)=cos(π/7)*[cos(2π/7)+cos(3π/7)]
Answer:
The answer would be (0, 2/3) or (0, Two-thirds)
