9514 1404 393
Answer:
(x, y) = (3.5, -4)
Step-by-step explanation:
Elimination is easiest if one of the coefficients of a variable is a multiple of the other coefficient of the variable. Here, we have x-coefficients of 4 and 8, so it will be easiest to eliminate x.
Subtract the second equation from 2 times the first.
2(4x +7y) -(8x +5y) = 2(-14) -(8)
9y = -36 . . . . . simplify
y = -4 . . . . . . . divide by 9
4x +7(-4) = -14 . . . . substitute for y in the first equation
4x = 14 . . . . . . . add 28
x = 3.5 . . . . divide by 4
The solution is (x, y) = (3.5, -4).
Answer:
The arc is one-third of the circumference.
Step-by-step explanation:
The area of a circumference = 2πr
C = 2πr ... (1)
If an arc subtends a central angle measuring 2π/3 rad,
The length of the arc = rθ
Given θ = 2π/3
Length of the arc L = r(2π)/3
L = 2πr/3... (2)
L = 1/3(2πr)
Since C = 2πr
L = 1/3C
This shows that the arc is one-third of the circumference.
Speed = distance/time Which in your case means 50 meters/ 21.34 seconds, which equals 2.343 meters per second.
Answer:
.
Step-by-step explanation:
Answer:
AB ≈ 15.7 cm, BC ≈ 18.7 cm
Step-by-step explanation:
(1)
Using the Cosine rule in Δ ABD
AB² = 12.4² + 16.5² - (2 × 12.4 × 16.5 × cos64° )
= 153.76 + 272.25 - (409.2 cos64° )
= 426.01 - 179.38
= 246.63 ( take the square root of both sides )
AB = 
≈ 15.7 cm ( to 1 dec. place )
(2)
Calculate ∠ BCD in Δ BCD
∠ BCD = 180° - (53 + 95)° ← angle sum in triangle
∠ BCD = 180° - 148° = 32°
Using the Sine rule in Δ BCD
= 
= 
( cross- multiply )
BC × sin32° = 12.4 × sin53° ( divide both sides by sin32° )
BC = 
≈ 18.7 cm ( to 1 dec. place )
