Answer:
JK = 42 , KL = 78
Step-by-step explanation:
JK + KL = JL , substitute values
4x + 6 + 7x + 15 = 129 , that is
11x + 21 = 120 ( subtract 21 from both sides )
11x = 99 ( divide both sides by 11 )
x = 9
Then
JK = 4x + 6 = 4(9) + 6 = 36 + 6 = 42
KL = 7x + 15 = 7(9) + 15 = 63 + 15 = 78
