We have to add 8/15 to 2/5.
To add two fractions we have to make them have the same denominator, so we have to convert 2/5 to have a denominator of 15. To do this, we have to multiply 2/5 by 3 and then we can add the fractions:

Answer: 14/15
Answer:
The answers would be as follows:
3
3
1
1
Step-by-step explanation:
We can tell that the first two have an infinite number of solutions because when we try to solve, we get a true statement. The first one is done for you below.
-6x + 7 = -6x + 7 ------> Add 6x to both sides
7 = 7 (TRUE STATEMENT)
We can tell the next two have no solution due to the fact that they develop a false statement when trying to solve.
-3x + 7 = 3x + 7 ----> Subtract 7 from both sides
-3x = 3x ---> Divide by 3
-x = x (UNTRUE STATEMENT)
The total area is 78 sq. ft.
Since the medal platform has different measurements, we need to individually compute the area of each polygon.
The top polygon is a square. Its sides measure 3 ft.
A₁ = a²
A₁ = 3 ft²
A₁ = 9 ft²
The middle polygon is a rectangle.
Its total width can be derived by adding the widths given and the width of the square above.
w = 3 ft + 3 ft + 3 ft
w = 9 ft
A₂ = width * height
A₂ = 9 ft * 2 ft
A₂ = 18 ft²
The bottom polygon is also a rectangle.
w = 4 ft + 9 ft + 4 ft
w = 17 ft
A₃ = width * height
A₃ = 17 ft * 3 ft
A₃ = 51 ft²
Total Area = A₁ + A₂ + A₃
T.A. = 9 ft² + 18 ft² + 51 ft²
T.A. = 78 ft²