i need help with writing expressions

A) double the sum of 25 and 8

i think it is(2x25+8)

Mr F says: 2x(25 + 8).
B) the quotient of 15 and 3 subtracted from the product of 4 and 9

i think it is (5/3-4x9)

C) the difference between 20 and 5 multiplied by the sum of 8 and 2

I think it is

(20-5

)x

(8+2

)
D) 3 times the

square root of the sum of

9 and 7 i think it is 3x

sqrt(9 +7) Mr F says: It's square root, not squared.
(2) = squared as i don't know how to write that on a computer.

any help would be greatful or just letting me know i'm on the right track i just can't seem to get it