-7x - 2y = -13
-7x + 7x - 2y = 7x - 13
-2y = 7x - 13
-2 -2
y = -3.5x + 6.5
x - 2y = 11
x - 2(-3.5x + 6.5) = 11
x - 2(-3.5x) - 2(6.5) = 11
x + 7x - 13 = 11
8x - 13 = 11
+ 13 + 13
8x = 24
8 8
x = 3
y = -3.5x + 6.5
y = -3.5(3) + 6.5
y = -10.5 + 6.5
y = -4
(x, y) = (3, -4)
First you need to know how many pounds of carbon dioxide you get when burning 1 gallon of gasoline. That number is 19.64 pounds
To get the number of pounds released when entire tank is burned you need to multiply gas tank volume and number of pounds you get when 1 gallon is burned.
17.2 * 19.64 = 337.808
x =
or x = - 
consider the factors of the product 6 × - 4 = - 24 which sum to the coefficient of the x- term ( + 5)
the factors are + 8 and - 3 ( split the middle term using these factors
6x² - 3x + 8x - 4 = 0 ( factor by grouping )
3x(2x - 1) + 4(2x - 1 ) ( take out common factor of (2x - 1) )
= (2x - 1)(3x + 4) = 0
equate each factor to zero and solve for x
2x - 1 = 0 ⇒ x = 
3x + 4 = 0 ⇒ x = - 
400,7,000 i think im not quit sure i dont know
We can check to see if (x - 2)(x - 9)(x - 1) is the factored form of x^3 + 8x^2 - 11x - 18 by using foil.
(x - 2)(x - 9)(x - 1)
(x - 2)x^2 - x - 9x + 9
Combine like terms.
(x - 2)x^2 - 10x + 9
FOIL again.
x^3 - 10x^2 + 9x - 2x^2 + 20x - 18
Combine like terms.
x^3 - 12x^2 + 29x - 18
<h3><u>The listed factors are not true factors of the given polynomial.</u></h3>