The law of cosines :
A^2 = B^2 + C^2 - 2BC cos A
2^2 = 3^2 + 4^2 - 2 . 3. 4 cos theta
= 21
hope this helps
Answer:
Step-by-step explanation:
5(2x+3) = 85
10x + 15 = 85
x = (85 - 15)/10
x = 7
Just substitute each number into the expression:
5(5) - 6(3) + 20(1/4)/4(3)(1/4) = 25 - 18 + 5/3 = 7 + 5/3 = 26/3 or 8 and 2/3.
6% tax means 6% of $3.50
Convert 6% to decimal (move decimal 2 spots to the left): 6% ⇒ .06
Multiply 3.50 with .06 = .21 <-- That's .21 cents of 3.50
That means you have to pay an extra 21 cents. Add that to the $3.50 you had to pay.
$3.50 + $0.21 = $3.71 <-- Price after tax