Brainliest + points

can you explain why choice c is correct? i'm confused how'd i got this wrong

The function v(r)=4/3pir^3 can be used to find the volume of air inside a basketball given its radius. what does v(r) represent

The value of x in this system of equations is 1. 3x + y = 9 y = –4x + 10 substitute the value of y in the first equation: combine like terms: apply the subtraction property of equality: apply the division property of equality: 3x + (–4x + 10) = 9 –x + 10 = 9 –x = –1 x = 1 what is the value of y?

Arectangle plot measure 20ft. by 30ft. a 3-ft.-wide sidewalk surrounds it.find the area of the sidewalk.