Advertisements
Advertisements
Question
Find which of the following equations are quadratic:
5x2 – 8x = –3(7 – 2x)
Solution
5x2 – 8x = –3(7 – 2x)
`\implies` 5x2 – 8x = 6x – 21
`\implies` 5x2 – 14x + 21 = 0; which is of the form ax2 + bx + c = 0.
∴ Given equation is a quadratic equation.
APPEARS IN
RELATED QUESTIONS
Check whether the following is the quadratic equation:
(x + 2)3 = 2x(x2 - 1)
John and Jivanti together have 45 marbles. Both of them lost 5 marbles each, and the product of the number of marbles they now have is 128. Form the quadratic equation to find how many marbles they had to start with, if John had x marbles.
Find the value of ‘m’, if the following equation has equal roots:
(m – 2)x2 – (5 + m)x + 16 = 0
Solve `(x - 3)/(x + 3) + (x + 3)/(x - 3) = 2 1/2`
Use the substitution y = 2x + 3 to solve for x, if 4(2x + 3)2 – (2x + 3) – 14 = 0.
Solve:
`2(x^2 + 1/x^2) - (x + 1/x) = 11`
`x^2+6x+5=0`
`sqrt3x^2+10x7sqrt3=0`
`9x^2-9(a+b)x+(2a^2+5ab+2b^2)=0`
An ordinary train takes 3 hours less for a j ourney of 360kms when its speed is increased by 1 Okm/ hr.Fnd the usual speed of the train.
