So ur going from a smaller shape to a larger shape....means the scale factor is more then 1. The scale factor is the number that u multiply the original shape by to get the other shape.
so lets look at DE...it is 2.....and D'E' is 6
so 2 * x = 6...with ur scale factor being x
2x = 6
x = 6/2
x = 3.....so the scale factor is 3....because multiplying the original shape by 3, gives u the other shape
RHS
=4x-27/0
=not defined=0
LHS
=x-2x+3x+4/7=2x+4/7=(14x+4)/7= 14x+4.
14x=-4
x=-4/14
X=-2/7
Let the number be n
3*n - 10=25
3*n=25+10
3*n=35
n=35/3=11*2/3=11.67