get the same roots every time.
Practice Set 2.4
1. Compare the given quadratic equations to the general form and write values of
a, b, c.
full
(1) x2 - 7x + 5 = 0
(2) 2m2 = 5m - 5 (3) y2 = 7y
2. Solve using formula.
(1) x2 + 6x + 5 = 0 (2) x2 – 3x - 2 = 0 (3) 3m2 + 2m - 7 = 0
(4) 5m2 - 4m - 2 = 0 (5) y2 + y = 2 (6) 5x2 + 13x + 8 = 0
Answers
Step-by-step explanation:
Compare the given quadratic equations to the general form and write values of a, b, c.
i. x2 – 7x + 5 = 0
ii. 2m2 = 5m – 5
iii. y2 = 7y
Solution:
i. x2 – 7x + 5 = 0
Comparing the above equation with
ax2 + bx + c = 0, we get
a = 1, b = -7, c = 5
ii. 2m2 = 5m – 5
∴ 2m2 – 5m + 5 = 0
Comparing the above equation with
am2 + bm + c = 0, we get
a = 2, b = -5, c = 5
iii. y2 = 7y
∴ y2 – 7y + 0 = 0
Comparing the above equation with
ay2 + by + c = 0, we get
a = 1, b = -7, c = 0
Question 2.
Solve using formula.
i. x2 + 6x + 5 = 0
ii. x2 – 3x – 2 = 0
iii. 3m2 + 2m – 7 = 0
iv. 5m2 – 4m – 2 = 0
v. y2 + \frac { 1 }{ 3 } y = 2
vi. 5x2 + 13x + 8 = 0
Solution:
i. x2 + 6x + 5 = 0
Comparing the above equation with
ax2 + bx + c = 0, we get
a = 1, b = 6, c = 5
∴ b2 – 4ac = (6)2 – 4 × 1 × 5
= 36 – 20 = 16
Maharashtra Board Class 10 Maths Solutions Chapter 2 Quadratic Equations Practice Set 2.4 1
∴ x = -3 + 2 or x = -3 -2
∴ x = -1 or x = -5
∴ The roots of the given quadratic equation are -1 and -5.