4s+7a=861
s+a=168
This can be solved using either elimination or substitution. I am going to use substitution.
Solve s+a=168 for s
s=168-a
Replace 168-a for s in 4s+7a=861
4(168-a)+7a=861
672-4a+7a=861
Solve for a
672+3a=861
3a=189
a=63
Substitute 63 for a in s=168-a
s=168-63=105
So, s=105 student tickets and a=63 adult tickets
Answer:
x = 20
Step-by-step explanation:
Assuming you require the value of x
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
7x - 15 is an exterior angle of the triangle, thus
7x - 15 = x + 28 + 4x - 3 , that is
7x - 15 = 5x + 25 ( subtract 5x from both sides )
2x - 15 = 25 ( add 15 to both sides )
2x = 40 ( divide both sides by 2 )
x = 20
Answer:
Step-by-step explanation:
Use law of cosines
c² = a² + b² - 2abcosθ
cosθ = (c² - a² - b²) / -2ab
c = length of AC = √(8 - 5)² + (4 - (-5))² = √90
b = length of AB = √(8 - 6)² + (4 - 3)² = √5
a = length of BC = √(6 - 5)² + (3 - (-5))² = √65
cosθ = (√90² - √65² - √5²) / -2√65√5
cosθ = 20 / -36.05551...
cosθ = - 0.5547001
θ = 123.69°
Answer:
180
Step-by-step explanation:
