Answer:Part 3) Miguel scored 29 points and Alonzo scored 25 pointsPart 4) Morgan's age is 14 1/2 years and Mr Santos' age is 29 1/2 yearsStep-by-step explanation:Part 3) Letx ----> the number of points that Miguel scoredy ---> the number of points that Alonzo scoredwe know that[tex]x+y=54[/tex] ----> equation A[tex]x=y+4[/tex] ----> equation Bsubstitute equation B in equation A and solve for y[tex](y+4)+y=54\\2y=54-4\\2y=50\\y=25[/tex]Find the value of x[tex]x=25+4=29[/tex]the solution is the point (29,25)That means ----> Miguel scored 29 points and Alonzo scored 25 pointsPart 4) Letx ----> Morgan's agey ---> Mr Santos' agewe know that[tex]x+y=44[/tex] -----> equation A[tex]x=y-15[/tex] ----> equation Bsubstitute equation B in equation A and solve for y[tex](y-15)+y=44\\2y=44+15\\2y=59\\y=29.5[/tex]Find the value of x[tex]x=29.5-15=14.5[/tex]the solution is the point (14.5,29.5)That means ----> Morgan's age is 14 1/2 years and Mr Santos' age is 29 1/2 years