Which of the following is a quadratic
equation ?
a) x2 + 2x +1 = ( 4-x)2 + 3
b)
-2 x2 = (5-x) (2x- 2/5)
c) (k+1) x2 +3/2 x =7 where k is not
equal to -1 d) x3 –x2 = (x-1)3
Select one:
O a. (k+1) x2 +3/2 x =7 where k is
not equal to -1
O b.-2 x2 = (5-x) (2x- 2/5)
O c. x2 + 2x +1 = ( 4-x)2 + 3
O d. x3 –x2 = (x-1)3
Answers
Answer:
x²+2x+1=(4-x)2+3 is the correct answer
Step-by-step explanation:
x²+2x+1=(4-x)2+3
x²+2x+1=8-2x+3
x²+2x+1=11-2x
Given,
A set of equations
To find,
Which of the following are linear equations?
Solution,
A quadratic equation is an equation that has a maximum power of 2
a) x²+2x+1=(4-x)²+3
x²+2x+1=16+x²-8x+3
x²+2x+1-(16+x²-8x+3)=0
x²+2x+1-16-x²+8x-3=0
10x-18=0
It is not a quadratic equation since it has a maximum power of 1.
b) -2 x² = (5-x) (2x- 2/5)
-2x²=5(2x²-2/5)-x(2x-2/5)
-2x²=10x²-2-2x²+(2/5)x
-10x²-(2/5)x+2=0
It is a quadratic equation since it has a maximum power of 2.
c) (k+1)x² +3/2 x =7 is a quadratic equation since it has a maximum power of 2.
d) x³ –x² = (x-1)³
x³ –x² = x³-1-3x²+3x
-x²+1+3x²-3x=0
2x²-3x+1=0
It is a quadratic equation since it has a maximum power of 2.
Hence, -10x²-(2/5)x+2=0, (k+1)x² +3/2 x =7 and 2x²-3x+1=0 are quadratic equation. Option (b), Option (c), Option (d)