Answer:
D. About 2700 in^2
Step-by-step explanation:
The area of a circle A = πd²/4 where d = diameter of circle.
A/d² = π/4 = k the proportionality constant.
So, A₁/d₁² = A₂/d₂² Now for circle A, Area = A₁ = 300 in² and diameter = d₁ = 20 inches. For circle B, Area = A₂ = unknown and diameter = d₂ = 60 inches.
So, we have
A₁/d₁² = A₂/d₂²
A₂ = A₁d₂²/d₁²
A₂ = A₁(d₂/d₁)²
substituting the values of the variables, we have
A₂ = 300 in²(60 in/20 in)²
A₂ = 300 in²(3)²
A₂ = 300 in²(9)
A₂ = 2700 in²
So, the area of circle B is about 2700 in²
We have the following vectors:
u = (a, b)
v = (c, d)
We observe that the vectors form an angle of 90 degrees.
Therefore, the product u.v is equal to zero.
We have then:
u.v = (a, b). (c, d) = 0
u.v = ac + bd = 0
ac = -bd
Answer:
B) ac = -bd
Answer:
1. 5
2. 5
3. -3
4.y= -1
5. 5
Step-by-step explanation:
1.)x- 2y= -25 ; y=3x
x-2(3x)=(-25)
x-6x=(-25) ; -5x=(-25) ; x=5
2.) 5x+3y =40; x=y
8y=40; y=5
3.) 4x-3y= -27; x=3y
4(3y)-3y= -27; 12y-3y=-27; 9y=-27; y=-3
4.)x-y=9; x=-8y; -8y-y=9; -9y=9; y=-1
5.) 2x+2y=30; y=2x ; 2x+2(2x)=30; 6x=30; x=5
5x+25 final answer is x=5