can someone correct these for me please...

Remove the parentheses.
-(3x+5y)

My answer: -3x-5y

Find the value of the polynomial

-x^2+3x-1 when x=4

My answer: -5

multiply. 10x(-4x-7)

my answer: -40x^2-70x

all correct.

awsome.....thank you...i just want to make sure....

You're welcome! I'm glad to hear that your answers are correct. It's always a good idea to double-check your work to ensure accuracy. If you have any more questions or need further assistance, feel free to ask!