Answer:
Step-by-step explanatio............................................
This isn’t a math equation
Answer:
Step-by-step explanation:
Use FOIL method
1) (x +4 )(3x +2) = x*3x + x*2 + 4*3x + 4*2
= 3x² + 2x + 12x + 8
= 3x² + 14x + 8
4) (4x - 1) (2x + 7) = 4x*2x + 4x*7 + (-1)*2x + (-1) * 7
= 8x² + 28x - 2x - 7
= 8x² + 26x - 7
The equation must equal 84, so you can eliminate B and D.
Chin charges a rate for 2 hours, then charges a reduced rate for 4 hours. There are no discounts present in his rate, so you can eliminate A.
The equation for Chin's charges can be found by the equation C. 2x + 4y = 84.
<span>tan(15) =
sin(15) / cos(15) =
sin(45 - 30) / cos(45 - 30) =
[ sin(45)cos(30) - sin(30)cos(45) ] / [ cos(45)cos(30) + sin(45)sin(30)]
Since sin(45) = cos(45) = √2/2, you can just factor that out from the top and bottom
[ cos(30) - sin(30) ] / [ cos(30) + sin(30)]
[ √3/2 - 1/2 ] / [ √3/2 + 1/2]
(√3 - 1) / (√3 + 1)
(√3 - 1)^2 / (√3+1)(√3 - 1)
(√3 - 1)^2 / (3 - 1)
(3 - 2√3 +1) / 2
2 - √3
There's also a formula for tan(a-b), but I couldn't remember it off hand.</span>
