BRAINLIEST Which equation could be solved using this application of the quadratic formula? A.
x2 + 1 = 2x − 3
B.
x2 – 2x − 1 = 3
C.
x2 + 2x − 1 = 3
D.
x2 + 2x − 1 = -3

Quadratic formula:  [ +/-   is   ± ]    

You can find the value of a, b, c  -->  ax² + bx + c = 0  

 Since this is not simplified, you can find a, b, c:

a = 1

b = 2

c = -4

A.)  x² + 1 = 2x − 3   Make the equation into ax² + bx + c = 0. Subtract 2x on both sides, and add 3 on both sides to set the equation equal to 0

x² + 1 - 2x + 3 = 2x - 2x - 3 + 3

x² - 2x + 4 = 0      

a = 1

b = -2

c = 4    This is not the answer because b = 2 not -2, and c = -4 not 4

B.) x² - 2x − 1 = 3     Subtract 3 on both sides to set the equation = 0

x² - 2x - 4 = 0

a = 1

b = -2

c = -4      This is not the answer because b = 2 not -2

C. x² + 2x - 1 = 3    Subtract 3 on both sides to set the equation = 0

x² + 2x - 4 = 0

a = 1

b = 2

c = -4    This is your answer

D. x² + 2x - 1 = -3      Add 3 on both sides to set the equation = 0

x² + 2x + 2 = 0

a = 1

b = 2

c = 2       This is not the answer because c = -4 not 2

d (5 x (-20)) * (100 x (0.7))

step-by-step explanation:

5÷1/100 * -.7 *-20

copy dot flip

5*100 * -.7 *-20

rearrange

5*-20   * 100 *-.7

-100   *-70

7000

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.