Question

3. 21 - 3 (x - 7) = x + 20 solve the following equation​

Answer 1

21 - 3 (x - 7) = x + 20

21 - 3x + 21 = x + 20

42 - 3x = x + 20

42 - 20 = x + 3x

22 = 4x

x = 22/4

x = 11/2

Answer 2

Given :

• An equation 21 - (x - 7) = x + 20

To Find :

• Value of x.

Solution :

Let's solve the equation

→ 21 - (x - 7) = x + 20

→ 21 - x + 7 = x + 20

→ 21 + 7 - x = x + 20

→ 28 - x = x + 20

→ 28 - 20 = x + x

→ 2x = 8

→ x = 8/2

→ x = 4

.°. Value of x is 4

Verification :

→ 21 - (x - 7) = x + 20

Put the value of x

→ 21 - (4 - 7) = 4 + 20

→ 21 - (-3) = 4 + 20

→ 21 + 3 = 4 + 20

→ 24 = 24

Hence, verified !