For the first figure
we have two structure that look like a circle
since the two figures look alike
let represent the figure by x
x + x = 16
2x = 16
divide both sides by 2
2x/2 = 16/2
x = 8
this means each of the figure is 8
for the second example
we have a sweet and the circle like structure
since the circle like figure is 8
let the sweet be y
y - 8 = 9
y = 8 + 9
y = 17
this means the sweet like figure is 17
the third figure
we have the circle, animal and sweet
circle x animal - sweet = 7
circle = 8
sweet = 17
but we dont know the value for the animal
let the animal be z
8 x z -7 = 17
8z - 7 = 17
collect the like terms
8z = 17 + 7
8z = 24
divide both sides by 8
8z/8 = 24/8
z = 3
this means the animal is 3