It is believed that 3/4 of our dreams involve people that we know
a. write an expression to describe the number of dreams that feature people you know if you have d dreams.

the 3rd on is correct

step-by-step explanation:

step-by-step explanation:

(3rd option) - c

step-by-step explanation:

this can be solved first with pythagorean theorem, which tells us to square both legs of the triangle and sum it. this will be equal to the square of the hypotenuse.

the hypotenuse is the side "opposite" the 90 degree angle, which is x.

so we can write using pythagorean theorem,

simplifying:

to further simplify this radical, we need to use the property  

thus