Ialso bought $7$ different postcards. how many ways can i send the postcards to my $3$ friends, so that each friend gets at least one postcard?

how do i count the restriction that each friend must get at least 1 or more postcards and the postcards are distinguishable?

Bruh how’s it gonna tell me incorrect answer when it was right

Abit confused about what you mean, but i think you might be referring to slope intercept form: y = mx + bin that case b, or the y intercept is already given.(0,-1)find the slope by using the formulay2 - y1/x2 - x1the final slope will be 4/2, equivalent to 2.now your equation should look like thisy = 4/2x -1sorry if this didn’t you out!