Find the quadratic curve of best fit for this data what is the best approximation

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

List x1, x2, x3, x4 where xi is the left endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 4 and x = 6. a 4, 4.5, 5, 5.5 b 4.5, 5, 5.5, 6 c 4.25, 4.75, 5.25, 5.75 d 4, 4.2, 5.4, 6

What percent of 18 is 24? and plz explain thx.