We know that
if ∠WCR=49°
then
measure arc WR=49°-------> by central angle
circumference C=2*pi*r
for r=7 in
C=2*pi*7-----> 43.96 in
if 360°(full circle) has a length of----------> 43.96 in
49°---------------> x
x=49*43.96/360-----> x=5.98 in
alternative method
applying the formula
L=(∅/360°)*2*pi*r
where
∅ is the angle in degrees
r is the radius
L=(49°/360°)*2*pi*7------> L=5.98 in
the answer is
5.98 in
You do this by moving all terms without y to the right hand side, and then divide the whole lot to keep a clean y= on the left hand side.
Moving to the other side is done by subtracting (or adding) a term from both sides. Effectively this looks like you're moving the term and flipping the sign.
So 2y + 18 = 4x changes into 2y +18 -18 = 4x -18 so 2y = 4x - 18. If you forget about the middle step, it looks like the +18 jumped to the other side and changed sign. That's all.
Second step is to change the 2y into y. You do that by dividing everything by 2. So 2y=4x-18 becomes y=2x-9
1. y=2x-9
2. y=3/2x - 6
3. y=4x+18
4. y=2x-12
5. y=-4x+18
6. y=2/3x+4
7. y=-1/4x-18/4
8. y=1/4x-18/4
9. y=1/4x+18/4
10. y=-1/4x+18/4
11. y=-3/2x+6
12. y=3/2x+6
13. y=-3/2x-6
14. y=-2/3x-4
15. y=2/3x+2/3
16. y=18-4x
A is a reflection over the y axis. C is a translation of 4 units downwards and D is a reflection over the c axis. Your answer is B, that is a translation of 3 units to the right
Any number to the power of 
is itself. So, 
.
Here are some more examples:
