An amount of ₹ 5000 is put into three investments at 6%, 7% and 8% per annum respectively. The total annual income from these investments is ₹358. If the total annual income from first two investments is ₹70more
than the income from the third, find the amount of each investment by the matrix method.
HINT: Let these investments be ₹x, ₹y and ₹z, respectively.
Then, x + y + z = 5000, …(i)
= 358 
6x + 7y + 8z = 35800 …(ii)
And, 
6x + 7y - 8z = 7000. …(iii)