Can someone with slipe-intercept of equation from graph problem !

Aphoto of a painting measured 13 x 17 inches the scale of the photo to the original painting is 1 inch to 3 inches. what is the size of this painting

How can you find the conditional probability of a given b as the fraction of b’s outcomes that also belong to a, and interpret the answer in terms of the model? i just need a good explanation

The suare root of 9x plus 7 plus the square rot of 2x equall to 7