There are many ways to do this depending on the property you have to use:
If you use the distributive property, you need to distribute 3/4 to -10 and 2/5. Distribute means you will multiply it so your resulting equation will be this:

Before you can add, you need to first make them like terms because you cannot add unlike fractions. Get the LCD and form your new equation:

Now you can just add them together to get:

and then simplify your fraction:

or -
The whole fraction becomes negative because when you divide integers and of them is negative, the final answer will be negative.
(4x+y)+5
20x+5y
20x+5y+0
third term is zero
Answer:
Alexander is incorrect because the expressions are not equivalent.
Step-by-step explanation:
If the expression is evaluated for any value of x, y; the result will not be same.
For instance, let assume x = 1 and y = 2
3x + 4y = 3 + 4 = 7
(3)(4) + xy = (3)(4) + (1 * 2) = 12 + 2 = 14
So, the expressions are not the same and Alexander is incorrect.
We need a picture of the shape.