Question

What must be added to the sum of x2-4x+7 and 2x2+5x-9 to get 0.​

Answer 1

What must be added to 5x3-2x2+6x+7 to make the

Let y be the "thing" to add to 5x^3 - 2x^2 + 6x +7 to equal x^3 + 3x^2 -x +1:

Therefore:

5x^3 - 2x^2 + 6x +7 + y = x^3 + 3x^2 - x + 1

Step 1: Rearrange equation and solve for y

y = x^3 + 3x^2 - x + 1 - (5x^3 - 2x^2 + 6x +7)

Step 2: Carry out multiplication of -1

y = x^3 + 3x^2 - x + 1 - (5x^3 - 2x^2 + 6x +7)

y = x^3 + 3x^2 - x + 1 - 5x^3 + 2x^2 - 6x - 7

Step 3: Rearrange equation

y = x^3 - 5x^3 + 3x^2 + 2x^2 -x - 6x + 1 -7

Step 4: Simplify equation by

y = (1 - 5)x^3 + (3 + 2)x^2 + (-1 -6)x + (1–7)

y = -4x^3 + 5x^2 - 7x -6

Therefore, if you add -4x^3 + 5x^2 - 7x -6 to 5x^3 - 2x^2 + 6x +7, you'll get x^3 + 3x^2 -x +1.

Answer 2

Answer:

your answer is in this photo