I'm pretty sure you are looking for factored forms as an equivalent equation, so here is how you do it.
This equation would be solved by difference of squares. 16, x^4, and 81 are all perfect squares ( which means that it is a number multiplied by itself, 16 is 4 x4 for example). So the first thing you want to do is recall the formula which is
(a^2 - b^2) = (a - b)*(a + b)
(16x^4 - 81)= 0
Find the sq. root of 16 which is 4, and of x^4 which is x^2, and 81 which is 9. Now re write it in the (a - b)*(a + b) format. ----> (4x^2 - 9)*(4x^2 + 9) = 0
1*5=12.75
2*4=9.6
so nine pens cost 3.15
one pen will be 0.35$
so one pencil will be .20$
Answer:
D
Step-by-step explanation:
The point you're looking for is the same distance from the origin, but 15° clockwise around a circle centered at the origin. Points A and D are the only ones with the same radius. Point D is the only one that is 15° clockwise from P.
_____
The approximate coordinates of the rotated point are (-4.3120, 3.2259).
im not sure what ur asking. but c is a line segment
