40 tangs of a mixture of sand and gravel is 30% sand. how many tangs of sand must be added to produce a mixture which is 40% gravel

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 always true about a positive integer raised to a negative odd power?

Rewrite the following quadratic functions in intercept or factored form. show your work. f(x) = 3x^2 - 12