1. Convert the following statements into equation and find the
solution for each:
a) If I take three- fourth of number and 3 to it ,I get 21.
class 7th
Answers
Answer:
(i) x + 3 = 0
L.H.S. = x + 3
By putting x = 3,
L.H.S. = 3 + 3 = 6 ≠ R.H.S.
∴ No, the equation is not satisfied.
(ii) x + 3 = 0
L.H.S. = x + 3
By putting x = 0,
L.H.S. = 0 + 3 = 3 ≠ R.H.S.
∴ No, the equation is not satisfied.
(iii) x + 3 = 0
L.H.S. = x + 3
By putting x = −3,
L.H.S. = − 3 + 3 = 0 = R.H.S.
∴ Yes, the equation is satisfied.
(iv) x − 7 = 1
L.H.S. = x − 7
By putting x = 7,
L.H.S. = 7 − 7 = 0 ≠ R.H.S.
∴ No, the equation is not satisfied.
(v) x − 7 = 1
L.H.S. = x − 7
By putting x = 8,
L.H.S. = 8 − 7 = 1 = R.H.S.
∴ Yes, the equation is satisfied.
(vi) 5x = 25
L.H.S. = 5x
By putting x = 0,
L.H.S. = 5 × 0 = 0 ≠ R.H.S.
∴ No, the equation is not satisfied.
(vii) 5x = 25
L.H.S. = 5x
By putting x = 5,
L.H.S. = 5 × 5 = 25 = R.H.S.
∴ Yes, the equation is satisfied.
(viii) 5x = 25
L.H.S. = 5x
By putting x = −5,
L.H.S. = 5 × (−5) = −25 ≠ R.H.S.
∴ No, the equation is not satisfied.
(ix) = 2
L.H.S. =
By putting m = −6,
L. H. S. = ≠ R.H.S.
∴No, the equation is not satisfied.
(x) = 2
L.H.S. =
By putting m = 0,
L.H.S. = ≠ R.H.S.
∴No, the equation is not satisfied.
(xi) = 2
L.H.S. =
By putting m = 6,
L.H.S. = = R.H.S.
∴ Yes, the equation is satisfied.