You can combine the same numbers with the same variables using the operation sign for each. For example, using your equation, you would combine the 3n and 4n which is 7n. So your equation would be
7n - 2
2x^2 + 4x + 1 = 0
2x^2 + 4x + 1 - 1 = 0 - 1
2x^2 + 4x = -1
X(2x + 4) = -1
X = -1.
2x + 4 = -1
2x + 4 - 4 = -1 - 4
2x = -5
2x/2 = -5/2
X = -5/2.
I believe these are the solutions. If not you can use the quadratic formula to solve for the roots, solutions.
(20)(7) = 140 hours per week
(20)(365) = 7300 hours per year
15y - 9 < 36
15y < 36 + 9
15y < 45
y < 45 ÷ 15
y < 3
