Distribute the 3a^n to all the other values then solve...
(3a^n*a^n)+(3a^n*a^n)+(3a^n*-1)
4a^2n+4a^2n-3a^n=
8a^2n-3a^n
One $10 bill, Two $1 bills, Two Quarters, Two Nickels
Two $5 bills, Two $1 bills, Two Quarters, Two Nickles
One $10 bill, One $1 bill, Six Quarters, Two Nickles
The answer could be .317
(not could be as in I don't know but could be as is it's an option)
~ Simplifying
-4x + -4 = -7(x + 4)
~ Reorder the terms:
-4 + -4x = -7(x + 4)
~ Reorder the terms:
-4 + -4x = -7(4 + x)
-4 + -4x = (4 * -7 + x * -7)
-4 + -4x = (-28 + -7x)
~ Solving
-4 + -4x = -28 + -7x
~ Solving for variable 'x'.
~ Move all terms containing x to the left, all other terms to the right.
~ Add '7x' to each side of the equation.
-4 + -4x + 7x = -28 + -7x + 7x
~ Combine like terms: -4x + 7x = 3x
-4 + 3x = -28 + -7x + 7x
~ Combine like terms: -7x + 7x = 0
-4 + 3x = -28 + 0
-4 + 3x = -28
~ Add '4' to each side of the equation.
-4 + 4 + 3x = -28 + 4
~ Combine like terms: -4 + 4 = 0
0 + 3x = -28 + 4
3x = -28 + 4
~ Combine like terms: -28 + 4 = -24
3x = -24
~ Divide each side by '3'.
x = -8
~ Simplifying
x = -8
Rate = 10/2 = 5 trees per hour
150trees/5 trees per hour = 30 hours
the answer is D = 30 hours