What is the reason for step 3 of this proof

Asquare is dilated by a scale factor of 1.25 to create a new square. how does the area of the new square compare with the area of the original square? a)the area of the new square is 1.25 times the area of the original square. b)the area of the new square is 2.50 times the area of the original square. c)the area of the new square is 1.252 times the area of the original square. d)the area of the new square is 1.253 times the area of the original square.

Which ordered pair (c,d) is a solution to the given system of linear equations- c+2d=13 -9c-4d=-15

It is given that the quadratic equation hx²-3x+k=0, where h and k are constants, has roots [tex] \beta \: and \: 2 \beta [/tex]express h in terms of k