Solve with Quadratics
1 answer:
Answer:
x = 1 ±
Step-by-step explanation:
Given
2x² - 4x = 10 ( divide through by 2 )
x² - 2x = 5
Using the method of completing the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(- 1)x + 1 = 5 + 1
(x - 1)² = 6 ( take the square root of both sides )
x - 1 = ± ( add 1 to both sides )
x = 1 ± ← exact solutions
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Answer:
the lower right matrix is the third correct choice
Step-by-step explanation:
Your problem statement shows that you have correctly selected the matrices representing the initial problem setup (middle left) and the problem solution (middle right).
Of the remaining matrices, the upper left is an incorrect setup, and the lower left is an incorrect solution matrix.
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We notice that in the remaining matrices on the right that the (2,3) term is 0, and the (3,2) and (3,3) terms are both 1.
The easiest way to get a 0 in the 3rd column of row 2 is to add the first row to the second. When you do that, you get ...
Already, we see that the second row matches that in the lower right matrix.
The easiest way to get 1's in the last row is to divide that row by 0.15. When we do that, the (3,4) entry becomes 2100/0.15 = 14000, matching exactly the lower right matrix.
The correct choices here are the two you have selected, and <em>the lower right matrix</em>.
