Эти числа 6 и 9, так как 6*9=54 и 6+9=15.
(t-7)^2-9t^2= (t-7-3t) (t-7+3t)= (-7-2t) (4t-7)= -(7+2t) (4t-7)
cos45⁰=√2/2; tg240⁰=tg(180⁰+60⁰)=tg60⁰=√3; sin120⁰=sin(90⁰+30⁰)=cos30⁰=√3/2;
ctg210⁰=ctg(180⁰+30⁰)=ctg30⁰=√3; cos150⁰=cos(90⁰+60⁰)=-sin60⁰=-√3/2;
tg225⁰=tg(180⁰+45⁰)=tg45⁰=1; sin150⁰=sin(90⁰+60⁰)=cos60⁰=½;
ctg240⁰=ctg(180⁰+60⁰)=ctg60⁰=1/√3.