CAN SOMEONE PLEASE HELP ME WITH THIS ITS DUE TODAY :)))

What is the sum or difference 4x10 – 9x10 (1 point) –5x10 –5x20 –36x10 –36x20 this is the cca test i need all the answers this is the first 2

Given that de, df, and ef are midsegments of △abc, and de=3.2 feet, ef=4 feet, and df=2.4 feet, the perimeter of △abc is .

Find the least common multiple of the expressions: 1. 3x^2, 6x - 18 2. 5x, 5x(x +2) 3. x^2 - 9, x + 3 4. x^2 - 3x - 10, x + 2 explain if possible