Which system of equations can you use to find the roots of the equation 2x3 + 4x2 – x + 5 = –3x2 + 4x + 9? y = 2x3 + x2 + 3x +5 y =9 y = 2x3 + x2 y = 3x + 14 y = 2x3 + 4x2 – x + 5 y = –3x2 + 4x + 9

The answer is y = 2x3 + 4x2 – x + 5 and  y = –3x2 + 4x + 9

Roots are both: x=-4, x= -1/2 , x= 1

Proof:

Solve for x over the real numbers:

2 x^3 + 4 x^2 - x + 5 = -3 x^2 + 4 x + 9

Subtract -3 x^2 + 4 x + 9 from both sides:

2 x^3 + 7 x^2 - 5 x - 4 = 0

The left hand side factors into a product with three terms:

(x - 1) (x + 4) (2 x + 1) = 0

Split into three equations:

x - 1 = 0 or x + 4 = 0 or 2 x + 1 = 0

Add 1 to both sides:

x = 1 or x + 4 = 0 or 2 x + 1 = 0

Subtract 4 from both sides:

x = 1 or x = -4 or 2 x + 1 = 0

Subtract 1 from both sides:

x = 1 or x = -4 or 2 x = -1

Divide both sides by 2:

 x = 1 or x = -4 or x = -1/2

Step-by-step explanation:

The answer is y = 2x3 + 4x2 – x + 5 and  y = –3x2 + 4x + 9

Roots are both: x=-4, x= -1/2 , x= 1

Explanation:

Solve for x over the real numbers:

2 x^3 + 4 x^2 - x + 5 = -3 x^2 + 4 x + 9

Subtract -3 x^2 + 4 x + 9 from both sides:

2 x^3 + 7 x^2 - 5 x - 4 = 0

The left hand side factors into a product with three terms:

(x - 1) (x + 4) (2 x + 1) = 0

Split into three equations:

x - 1 = 0 or x + 4 = 0 or 2 x + 1 = 0

Add 1 to both sides:

x = 1 or x + 4 = 0 or 2 x + 1 = 0

Subtract 4 from both sides:

x = 1 or x = -4 or 2 x + 1 = 0

Subtract 1 from both sides:

x = 1 or x = -4 or 2 x = -1

Divide both sides by 2:

 x = 1 or x = -4 or x = -1/2

d

step-by-step explanation:

d

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.