Answer:
y = - 19
Step-by-step explanation:
Express 210 and 55 as products of their prime factors, that is
210 = 2 × 3 × 5 × 7
55 = 5 × 11
Identify the prime factors that both numbers have in common and multiply them.
Here only 5 is common, thus
HCF = 5
Thus
5 = 210 × 5 + 55y, that is
5 = 1050 + 55y ( subtract 1050 from both sides )
- 1045 = 55y ( divide both sides by 55 )
y = - 19
