Can you explain how to decompose a rectangle into congruent triangles? how does the area of the decomposed pieces relate to the area of the rectangle?

What is the range? can’t seem to find it out

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?

What is negative 3/9 times negative 2/8 ?