Question

Check whether the value given in the brackets is a solution to the given equation or not:

(a) n + 5 = 19 (n = 1) (b) 7n + 5 = 19 (n = − 2)

(c) 7n + 5 = 19 (n = 2) (d) 4p − 3 = 13 (p = 1)

(e) 4p − 3 = 13 (p = − 4) (f) 4p − 3 = 13 (p = 0)

Answer 1

(a) n + 5 = 19 (n = 1)

Putting n = 1 in L.H.S.,

n + 5 = 1 + 5 = 6 ≠ 19

As L.H.S. ≠ R.H.S.,

Therefore, n = 1 is not a solution of the given equation, n + 5 = 19.

(b) 7n + 5 = 19 (n = −2)

Putting n = −2 in L.H.S.,

7n + 5 = 7 × (−2) + 5 = −14 + 5 = −9 ≠ 19

As L.H.S. ≠ R.H.S.,

Therefore, n = −2 is not a solution of the given equation, 7n + 5 = 19.

(c) 7n + 5 = 19 (n = 2)

Putting n = 2 in L.H.S.,

7n + 5 = 7 × (2) + 5 = 14 + 5 = 19 = R.H.S.

As L.H.S. = R.H.S.,

Therefore, n = 2 is a solution of the given equation, 7n + 5 = 19.

(d) 4p − 3 = 13 (p = 1)

Putting p = 1 in L.H.S.,

4p − 3 = (4 × 1) − 3 = 1 ≠ 13

As L.H.S ≠ R.H.S.,

Therefore, p = 1 is not a solution of the given equation, 4p − 3 = 13.

(e) 4p − 3 = 13 (p = −4)

Putting p = −4 in L.H.S.,

4p − 3 = 4 × (−4) − 3 = − 16 − 3 = −19 ≠ 13

As L.H.S. ≠ R.H.S.,

Therefore, p = −4 is not a solution of the given equation, 4p − 3 = 13.

(f) 4p − 3 = 13 (p = 0)

Putting p = 0 in L.H.S.,

4p − 3 = (4 × 0) − 3 = −3 ≠ 13

As L.H.S. ≠ R.H.S.,

Therefore, p = 0 is not a solution of the given equation, 4p − 3 = 13.