Answer:
100-36x^2y^2
Step-by-step explanation:
100-36x^2y^2 =
(10-6xy)(10+6xy)
Because x^2-y^2 = (x+y)(x-y)
Answer:
20/21.
Step-by-step explanation:
tan X = opposite side / adjacent side
= 20/21.
You can use this memory aid for the 3 main trigonometric ratios:
SOH-CAH-TOA:
SineOppositeHypotenuseCosineAdajacentHypotenuseTangentOppositeAdjacent.

notice, is an arithmetic sequence, simply adding 6 to get the next term's value.
21 × 10 = 210
210 ÷ 55 = 3.82
3.82 ÷ 10 =0.382