Find the probability if there are 150 students and 45 of them play football

Parks is wearing several rubber bracelets one third of the bracelets are tie-dye 1/6 are blue and 1/3 of the remainder are camouflage if parks wears 2 camouflage bracelets how many bracelets does he have on

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1

X+ y = 5 ; x - y =3 solve using linear combination