Como calcular la fracción del total que representa una cantidad

What does x = in this equation x+3+2x=x+5

Need an artist designed a badge for a school club. figure abcd on the coordinate grid below shows the shape of the badge: the badge is enlarged and plotted on the coordinate grid as figure jklm with point j located at (2, -2) and point m is located at (5, 4). which of these could be the coordinates for point l? a. (2, 4) b. (8, 4) c. (5, 1) d. (5, 7)

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?