Here is the answer for a:
Let x and y represent the numbers of gallons used by the 40 mpg and 35 mpg cars, respectively.
.. x +y = 40 . . . . . . . . . . .total consumption is 40 gallons
.. 40x +35y = 1525 . . . . total miles driven = 1525
Multiply the first equation by 40 and subtract the second.
.. 40(x +y) -(40x +35y) = 40(40) -(1525)
.. 5y = 75
.. y = 15
.. x = 40 -15 = 25
The 40 mpg car consumed 25 gallons.
The 35 mpg car consumed 15 gallons.
Answer:
θ = 2π/3 or 5π/3
Step-by-step explanation:
2 cosθ + 1= 0
when + 1 goes to R H S Side than it becomes negative by transposition method
2 cos = -1
now by dividing by 2 both sides we get
cosθ = -
since cosθ is negative
Cosθ = - cos 60°
it means either cosθ lies in 2nd or third quadrant
θ = π - π/3
or
θ = 2π- π/3
so θ = 2π/3 or 5π/3