21 because you just multiply the 2 numbers.
Step-by-step explanation:
1/sin^2A -cos^2A/sin^2 A. ~tan = sin/cos
(1-cos^2)/sin^2A. ~ take lcm
sin^2A/sin^ A. ~ 1-cos^2A = sin^2A
1
for more free ans check bio
Answer:
You have to take 15 pens to get at least one red pencil.
Step-by-step explanation:
If there were one red and 6 green pens, there would be more red than green pens.
If there were 3 or more blue and thus 18 or more green pens, the number of pens would be over 20.
So there must be 2 blue, 12 green and thus 6 red pencils. So you have to take at least 15 pens to be sure that you got a red one.
2 + 4(3+2x) = 3x + 8
2 + 12 + 8x = 3x + 8
14 - 8 = 3x - 8x
6 = -5x
x = -6/5