Answer:
4th option
Explanation:
given the triangles are similar , then the ratios of corresponding sides are in proportion.
corresponding sides are 9 and 6 , 12 and x - 4 , then
=
← proportion equation ( cross- multiply )
9(x - 4) = 6 × 12 = 72 ( divide both sides by 9
x - 4 = 8 ( add 4 to both sides )
x = 12