Answer:
Step-by-step explanation:
1)
(x-3)/18=12/9, cross multiply
9(x-3)=18(12)
9x-27=216, add 27 to each side
9x=243, divide each side by 9
x=27
2)
(x-16)/(x+6)=3/5, cross multiply
5(x-16)=3(x+6)
5x-80=3x+18, subtract 3x from each side
2x-80=18, add 80 to each side
2x=98, divide each side by 2
x=49
3)
Since the triangles are similar we can say that
25/(4x-1)=10/(x+5), cross multiply
25(x+5)=10(4x-1)
25x+125=40x-10, subtract 40x from each side
-15x+125=-10, subtract 125 from each side
-15x=-135, divide each side by -15
x=9
