Minus 16x both sides and add 28 to both sides
x^2-16x+28=0
factor
hmm, what 2 numbers multiply to 28 and add to -16
hmm
1 and 28? nope
2 and 14? yep
since middle term is negative and last tem is positive, both of the factors are negative
(x-14)(x-2)=0
set each to zero
x-14=0
x=14
x-2=0
x=2
x=2 and 14
Answer:
see explanation
Step-by-step explanation:
(1)
the sine of an angle = 
(a)
here the opposite is 12 and the hypotenuse is 13
12 is the side opposite ∠DEF ← required angle
(b)
the tangent of an angle = 
here the opposite is 5 and the adjacent is 12
∠DFE ← required angle
(2)
to calculate AB use Pythagoras' identity in the right triangle
AB² = 2² + 3² = 4 + 9 = 13, hence
AB =
≈ 3.6 ( to nearest tenth )
tanB =
⇒ B = 33.7°
tanA =
⇒ A = 56.3°