Answer:
21
Explanation:
The side opposite 6 in the small triangle is 2x-7-14 which is 2x - 21
Proportion
6/18 = (2X - 21)/(2x - 7) Cross Multiply
6*(2x - 7) = 18*(2x - 21) Divide both sides by 6
2x - 7 = 3*(2x - 21) Remove the brackets
2x - 7 = 6x - 63 Add 63 to both sides
2x - 7 + 63 = 6x
2x + 56 = 6x Subtract 2x from both sides
56 = 4x Divide by 4
56/4 = 4x/4
x = 14
Answer
2x - 7
2*14 - 7
28 - 7
2x - 7 = 21