My tinky winky dippsie hurts

Which of the following lines is parallel to x=4? a- 3y=9 b- y=4 c- x=2 d- x=y answer this as soon as possible xoxo lo ; )

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?