Answer:
They used 6 vans and 3 buses
Step-by-step explanation:
x + y= 9
13x + 40y= 198
x= 9 - y
13(9 - y) + 40y= 198
117 - 13y + 40y= 198
27y= 81
y= 3
9-3= 6
4 cos² x - 3 = 0
4 cos² x = 3
cos² x = 3/4
cos x = ±(√3)/2
Fixing the squared cosine doesn't discriminate among quadrants. There's one in every quadrant
cos x = ± cos(π/6)
Let's do plus first. In general, cos x = cos a has solutions x = ±a + 2πk integer k
cos x = cos(π/6)
x = ±π/6 + 2πk
Minus next.
cos x = -cos(π/6)
cos x = cos(π - π/6)
cos x = cos(5π/6)
x = ±5π/6 + 2πk
We'll write all our solutions as
x = { -5π/6, -π/6, π/6, 5π/6 } + 2πk integer k
Answer:
18
Step-by-step explanation:
Sum the parts of the ratio, 3 + 4 = 7
Divide the amount of marbles by 7 to find the value of one part of the ratio
42 ÷ 7 = 6 ← value of 1 part of the ratio, thus
red marbles = 3 × 6 = 18
Well you would do 6% times 2000 (.06 *2000) 120
