Question

Find the value of:

2.12 - 0.45

Answer 1

Let x = 2.12    ....(i)
⇒ 100x = 212.12    ....(ii)
Subtracting (i) from (ii),
99x = 210
⇒  x = `(210)/(99)`
= `(70)/(33)`
Let y = 0.45
⇒  10y = 4.5   ....(iii)
⇒  100y = 45.5    ....(iv)
Subtracting (iii) from (iv),
90y = 41
⇒  y = `(41)/(90)`
∴ 2.12 - 0.45 = x - y
= `(70)/(33) - (41)/(90)`

= `(70 xx 30 - 41 xx 11)/(990)`

= `(2100 - 451)/(990)`

= `(1649)/(990)`
= 1.665