MP Board Class 7th Maths Solutions Chapter 4 Simple Equations Ex 4.2

October 16, 2021

Question 1.
Give first the step you will use to separate the variable and then solve the equation:
(a) x – 1 = 0
(b) x + 1 = 0
(c) x – 1 = 5
(d) x + 6 = 2
(e) y – 4 = -7
(f) y – 4 = 4
(g) y + 4 = 4
(h) y + 4 = -4
Solution:
On adding 1 to both sides of the given equation, we obtain
x – 1 + 1 = 0 + 1 ⇒ x = 1

(b) x + 1 = 0
On subtracting 1 from both sides of the given equation, we obtain
x + 1 – 1 = 0 – 1 ⇒ x = -1

(d) x + 6 = 2
On subtracting 6 from both sides of the given equation, we obtain
x + 6 – 6 = 2 – 6 ⇒ x = -4

(e) y – 4 = – 7
On adding 4 to both sides of the given equation, we obtain
y – 4 + 4 = -7 + 4 ⇒ y = -3

(f) y – 4 = 4
On adding 4 to both sides of the given equation, we obtain
y – 4 + 4 = 4 + 4 ⇒ y = 8

(g) y + 4 = 4
On subtracting 4 from both sides of the given equation, we obtain
y + 4 – 4 = 4 – 4 ⇒ y = 0

(h) y + 4 = -4
On subtracting 4 from both sides of the given equation, we obtain
y + 4 – 4 = – 4 – 4 ⇒ y = -8

Question 2.
Give first the step you will use to separate the variable and then solve the equation:

On dividing both sides of the given equation by 3, we obtain

(b) b2 = 6
On multiplying both sides of the given equation by 2, we obtain

(d) 4x = 25
On dividing both sides of the given equation by 4, we obtain

(e) 8y = 36
On dividing both sides of the given equation by 8, we obtai

(f) z3=54
On multiplying both sides of the given equation by 3, we obtain

(g) a5=715
On multiplying both sides of the given equation by 5, we obtain

(h) 20t = -10
On dividing both sides of the given equation by 20, we obtain

Question 3.
Give the steps you will use to separate the variable and then solve the equation:

Question 4.
Solve the following equations:

(f) 3s = -9
(g) 3s + 12 = 0
(h) 3s = 0
(i) 2q = 6
(j) 2q – 6 = 0
(k) 2q + 6 = 0
(l) 2q + 6 = 12
Solution:
MP Board Class 7th Maths Solutions Chapter 4 Simple Equations Ex 4.2 15