What value of c makes x2+6x+c a perfect square trinomial? 3,6,9,12

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?

Askateboard ramp is in the shape of a right triangle what is the height of the ramp

Define the type of sequence below. 7, 14, 28, 56, 112, a. neither arithmetic nor geometric b. arithmetic c. both arithmetic and geometric d. geometric