Answer:
E = 8
Step-by-step explanation:
y - x = 4
y - (3y) = 4
y - 3y = 4
2y = 4
y = 4/2
y = 2
x = 3y
x = 3×2
x = 6
x + y = 2+6
x+y = 8
Answer:

Step-by-step explanation:

Answer:
The only difference is that we line up the numbers according to the decimal point. For addition, it doesn't matter which number goes on the bottom.
Answer: first option.
Step-by-step explanation:
The ratio of the area of the triangles can be calculated as following:

Where
is the lenght of the given side of the smaller triangle and
is the lenght of the given side of the larger triangle.
Therefore:

It can be written as following:

The ratio of the perimeter is:

Where
is the lenght of the given side of the smaller triangle and
is the lenght of the given side of the larger triangle.
Therefore:

It can be written as following:

Answer:
m∠BCD = 140°
Step-by-step explanation:
ABCD is cyclic quadrilateral. A property of cyclic quadrilateral states that the opposite angles of it sum up to 180°. Here:
m∠A + m∠C =180° and m∠B + m∠D = 180°
So, m∠A + m∠C =180°
m∠A = 40° (given in the question)
40° + m∠C = 180°
m∠C = 180° - 40° = 140°
∴m∠C = m∠BCD = 140°