I need help on all three word problems

Find the sum of 4x^{2} -4+6 and -7^{2} +3x+1

11. minitab software was used to find the lsrl for a study between x=age and y=days after arthroscopic shoulder surgery until an athlete could return to their sport. use the output to determine the prediction model and correlation between these two variables. predictor coef se coef t p constant -5.054 4.355 -1.16 0.279 age 0.2715 0.1427 1.9 0.094 r-sq = 31.16%

What is the best approximation for the area of a circle with a radius of 4 m ? use 3.14 to approximate pi