Answer: 7
Step-by-step explanation:
8x +5 = 61
subtract 5 from both sides
8x = 56 divide both sides by 8 to get x by itself
x= 7
Distance=amount of gas times miles per gallon
distance=y
amount of gas=x
mpg=?
given
y=300
x=10
300=10 times ?
divide both sidesj by 10
30=?
equation is
y=x times 30 or
y=30x
Answer:
Solution:
the boat's speed in still water: x
The speed with current: (x+3)
The speed against current: (x-3)
The equation is
3(x+3) = 4(x-3)
x = 21 mph
The distance = 3*(21+3)= 72 miles
I choose (A)
Step-by-step explanation:
tan2x*cotx - 3 = 0
We know that: tan2x = sin2x/cos2x and cotx = cosx/sinx
==> sin2x/cos2x *cosx/sinx = 3
Now we know that sin2x = 2sinx*cosx
==> 2sinxcosx/cos2x * cosx/sinx = 3
Reduce sinx:
==> 2cos^2 x/ cos2x = 3
Now we know that cos2x = 2cos^2 x-1
==> 2cos^2 x/(2cos^2 x -1) = 3
==> 2cos^2 x = 3(2cos^2 x -1)
==> 2cos^2 x = 6cos^2 x - 3
==> -4cos^2 x= -3
==> 4cos^2 x = 3
==> cos^2 x = 3/4
==> cosx = +-sqrt3/ 2
<span>==> x = pi/6, 5pi/6, 7pi/6, and 11pi/6</span>
