Letter D
A = 135°
B = 30°
cosAcosB - sinAsinB = cos(A+B)
cos(135°+30°)
cos(165°)
X= 7
y=77
im not 100% though
Answer:
x = -1 + 2 sqr2
or
x = -1 -2 sqr2
Step-by-step explanation:
Answer:
D: 12
Step-by-step explanation:
The entire segment KI is composed of the segments KJ and JI. So:

We know that KI is 15.
KJ is (2x-15) and JI is (2x-6). Substitute:

Solve for x. Combine like terms:

Add 21 to both sides:

Hence, the value of x is:

We know that JI is 2x-6.
We will substitute 9 for x to find JI. So:

Hence, our answer is D.