Find lengths using Theorem 10.14 EXAMPLE 1 Find lengths using Theorem 10.14 ALGEBRA Find ML and JK. SOLUTION NK NJ = NL NM Use Theorem 10.14. x (x + 4) = (x + 1) (x + 2) Substitute. x2 + 4x = x2 + 3x + 2 Simplify. 4x = 3x + 2 Subtract x2 from each side. x = 2 Solve for x.
EXAMPLE 1 Find lengths using Theorem 10.14 Find ML and JK by substitution. SOLUTION ML = ( x + 2 ) + ( x + 1) JK = x + ( x + 4) = 2 + 2 + 2 + 1 = 2 + 2 + 4 = 7 = 8
Standardized Test Practice EXAMPLE 2 Standardized Test Practice SOLUTION RQ RP = RS RT Use Theorem 10.15. 4 (5 + 4) = 3 (x + 3) Substitute. 36 = 3x + 9 Simplify. 9 = x Solve for x ANSWER The correct answer is D.
GUIDED PRACTICE for Examples 1 and 2 Find the value(s) of x. SOLUTION = 6 (6 + 9) Use Theorem 10.15. 90 = 5x + 25 Simplify. 13 = x Solve for x
GUIDED PRACTICE for Examples 1 and 2 Find the value(s) of x. SOLUTION = (4) (6) Substitute. 3x = 24 Simplify. x = 8 Solve for x.
GUIDED PRACTICE for Examples 1 and 2 Find the value(s) of x. SOLUTION = (x+1)(x + 1 + x – 1) Use Theorem 10.15. 3x + 15 = 2x2 + 2x Simplify. 0 = 2x2 – x – 15 Combine Like Terms. 0 = (x – 3) (2x + 5) Solve for x 3 = x Use positive solution