Given the equation ax + b = 9x + 21 which set of values for a and b would result in an equation with infinity many solutions a = 3,b = 7
a = 9, b = 9
a = 9, b = -21
a = 9, b = 21

The triangles are similar. what is the value of x? x=

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?

Which expressions equal 9 when x=4 and y=1/3 a. x2+6y b. 2x + 3y c. y2-21x d. 5 (x/2) -3y e. 3x-9y