Draw quick picture and write to explain how to break addends to find the sum of 324+231

#12 find the value of x. #13 find the value of the variable.

For each proportion find the unknown number x 1/5/8=×/15

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?