Answer:
#7. JK = 1
Step-by-step explanation:
So all these problems are similar in the fact that you are given three pieces of information and you need to determine x. Let's look at #7.
We are to find the length JK but we are given it in terms of x. To find the length, we need to find x. Using the information we have about KL and JL, we can find this. Note, the value of JL is 5, and the value of KL is x + 8.
JK + KL = JL
( 2x + 9 ) + ( x + 8 ) = 5
3x + 17 = 5
3x = -12
x = -4
Now that we have the value of x, we can find the value of JK:
JK = 2x + 9
JK = 2(-4) + 9
JK = -8 + 9
JK = 1
Hence, the length of JK is 1.
Using this same basic idea, you can solve all of these problems.
Cheers.