pick out the solution from the values given in the brackets next to each equation.
show that the other values do not satisfy the equation.
a)n+12=18 (5,6)
b)r-4=1 (6,5)
Answers
Answer:
(a) 5m=60
Putting the given values in L.H.S.,
5 x 10 = 50, 5 x 5 = 25
∵ L.H.S. ≠ R.H.S. ∵ L.H.S.≠ R.H.S.
∴m=10 is not the solution. ∴m=5 is not the solution.
5 x 12 = 60, 5 x 15 = 75
∵ L.H.S. = R.H.S. ∵ L.H.S. ≠ R.H.S.
∴m=12 is a solution. ∴m=15 is not the solution.
(b) n+12=20
Putting the given values in L.H.S.,
12 + 12 = 24, 8 + 12 = 20
∵ L.H.S. ≠ R.H.S. ∵ L.H.S. = R.H.S.
∴n=12 is not the solution. ∴n=8 is a solution.
20 + 12 = 32, 0 + 12 = 12
∵ L.H.S. ≠ R.H.S. ∵ L.H.S. ≠ R.H.S.
∴n=20 is not the solution. ∴n=0 is not the solution.
(c) p–5=5
Putting the given values in L.H.S.,
0 – 5 = –5, 10 – 5 = 5
∵ L.H.S. ≠ R.H.S. ∵ L.H.S. = R.H.S.
∴p=0 is not the solution. ∴p=10 is a solution.
5 – 5 = 0, –5 – 5 = –10
∵ L.H.S. ≠ R.H.S. ∵ L.H.S. ≠ R.H.S.
∴p=5 is not the solution. ∴p=–5 is not the solution.
(d) \frac{q}{2}=72q=7
Putting the given values in L.H.S.,
\frac{7}{2}\frac{2}{2}=12722=1
∵ L.H.S. ≠ R.H.S. ∵ L.H.S. ≠ R.H.S.
∴q=7 is not the solution. ∴q=2 is not the solution.
\frac{10}{2}=5\frac{14}{2}=7210=5214=7
∵ L.H.S. ≠ R.H.S. ∵ L.H.S. = R.H.S.
∴q=10 is not the solution. ∴q=14 is a solution.
(e) r–4=0 Putting the given values in L.H.S.,
4 – 4 = 0, –4 – 4 = –8
∵ L.H.S. = R.H.S. ∵ L.H.S. ≠ R.H.S.
∴r=4 is a solution. ∴r=–4 is not the solution.
8 – 4 = 4, 0 – 4 = –4
∵ L.H.S. ≠ R.H.S. ∵ L.H.S. ≠ R.H.S.
∴r=8 is not the solution. ∴r=0 is not the solution.
(f) x+4=2
Putting the given values in L.H.S.,
–2 + 4 = 2, 0 + 4 = 4
∵ L.H.S. = R.H.S. ∵ L.H.S. ≠ R.H.S.
∴x=–2 is a solution. ∴x=0 is not the solution.
2 + 4 = 6, 4 + 4 = 8
∵ L.H.S. ≠ R.H.S. ∵ L.H.S. ≠ R.H.S.
∴x=2 is not the solution. ∴x=4 is not the solution.