Answer:
4
Step-by-step explanation:
15x+20 = 40 +10x
x = 4
<span>A rectangle is twice as long as it is wide. it's width is 5 1/2 cm. find the area of the rectangle.</span>
answer: 60 1/2 cm.
Recall the sum identity for cosine:
cos(a + b) = cos(a) cos(b) - sin(a) sin(b)
so that
cos(a + b) = 12/13 cos(a) - 8/17 sin(b)
Since both a and b terminate in the first quadrant, we know that both cos(a) and sin(b) are positive. Then using the Pythagorean identity,
cos²(a) + sin²(a) = 1 ⇒ cos(a) = √(1 - sin²(a)) = 15/17
cos²(b) + sin²(b) = 1 ⇒ sin(b) = √(1 - cos²(b)) = 5/13
Then
cos(a + b) = 12/13 • 15/17 - 8/17 • 5/13 = 140/221
5x = 15
x = 3
3(3) - 5y = -16
9 - 5y = -16
5y = -16 - 9
5y = - 25
y = - 5
(3, -5)
1/7 is your answer. It can't be reduced any further. If there is supposed to be a problem, next time, add it.
