How can you use mental math and estimation to decide

Ill mark the brainliest if you me with the these three questions 7,8,9

Heather is writing a quadratic function that represents a parabola that touches but does not cross the x-axis at x = -6. which function could heather be writing? fx) = x2 + 36x + 12 = x2 - 36x - 12 f(x) = -x + 12x + 36 f(x) = -x? - 12x - 36

Aboard 60 in. long is cut two parts so that the longer piece is 5 times the shorter. what are the length of the two pieces?