X = a + bi
y = c + di
xy = yx
(a + bi)(c + di) = (c + di)(a + bi)
a(c + di) + bi(c + di) = c(a + bi) + di(a + bi)
a(c) + a(di) + bi(c) + bi(di) = c(a) + c(bi) + di(a) + di(bi)
ac + adi + bci + bdi² = ac + bci + adi + bdi²
ac + adi + bci - bd = ac + bci + adi - bd
Answer:
center = (2, -4)
radius = 4
Step-by-step explanation:
Equation of a circle: 
(where (h, k) is the center and r is the radius)
Therefore,
- center = (2, -4)
- radius = √16 = 4
Answer:
Step-by-step explanation:
2(20 + 22) = 2(42) = 84 total books
Answer:
The length of the pother piece of the wood is 25 cm.
Step-by-step explanation:
Let the length of a piece of wood is x such that the ratio of two pieces is 2:5. Two pieces are 2x and 5 x
Length of the first piece is 10 cm. It means, 2x = 10 i.e. x = 5
We have considered that the length of other piece is 5x. It means 5×5 = 25 cm.
Hence, the length of the pother piece of the wood is 25 cm
Here are a few reasons:
The triangles have the same three sides
The triangles have the same three angles
The triangles could perfect overlap one another
They have corresponding angles.
Not sure if this helped but I hope so!
