Distribute the negative sign

Combine like terms
-9x^2 + 7x^2 = -2x^2
9x - 3x = 6x
13 - 6 = 7

<u>Answer</u>

1500 - 400 = how much sodium u can consume for the rest of the day
Maybe if you payed attention in class you would know.
Use inverse cosine here because you have the side adjacent to angle A and the hypotenuse. On your calculator, press the 2nd key then cosine to see this on your display

then enter 8/17 to give you an angle measure of 62 degrees.