How do you get the rule of 1,3,6,10,15,21,28

Write an expression that has three terms and simplifies to 4x - 7. identify the coefficient(s) and constant(s) in your expression

Kyle and elijah are planning a road trip to california. their car travels 3/4 of a mile per min if they did not stop driving, how many miles could kyle and elijah drive in a whole day? ? 1 day = 24 hours. plzzz i will give you 100 points

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'