Question

which the following is a quadratic equation
(a) x² + 2x + 1 = (4 -x)² + 3
(b) -2x² = (5 - x) (2x - 2/5)
(c) (k + 1) x² + 3/2 x = 7, where k = -1
d) x³ - x² = (x-1) ³​

Answer 1

Step-by-step explanation:

Note:

To be quadratic equation expression should be in the form of

4y

Solution :

${x}^{2} + 2x + 1 = {(4 - x)}^{2} + 3 \\ = > {x}^{2} + 2x + 1 = {4} ^{2} - 2 \times 4 \times x + {x}^{2} + 3 \\ = > {x}^{2} + 2x + 1 = 16 - 8x + {x}^{2} + 3 \\ = > {x}^{2} - {x}^{2} + 2x + 8x + 1 - 18 = 0 \\ = > 10x - 17 = 0 \\ it \: is \: not \: a \: qudratic \: equation \: because \: its \: in \: the \: \\ form \: of \: standard \: equation$

Answer 2

Answer:

D

Step-by-step explanation:

x³ - x² = (x-1)³

           = x³ - 1³ - 3x (x-1)

           = x³ - 1³ - 3x² + 3x

-x²  +  3x²  +1  -3x = 0

2x² - 3x + 1  =  0

its in the form ax² + bx + c = 0, therefore its a quadratic equation