Question

what must be subtracted from x³-8x²+7x-1 to get 3x³+x²-8x+1?​

Answer 1

Step-by-step explanation:

What amount is to be repaid on a loan of 12000 rs. For ¹1/2 years at 10% per annum compounded half yearly

Answer 2

Answer:

Let the number be a

$if \: we \: subtract \: a \: from \: x {}^{3} - 8x {}^{2} + 7x - 1 \: to \: get \: 3x {}^{3} + x {}^{2} - 8x + 1$

we can write it as:

$(x {}^{3 } - 8x {}^{2} + 7x - 1) + a = 3x {}^{3} + x {}^{2} - 8x + 1$

To find 'a' , take all the values of left hand side towards right except 'a' , we get

$= > a = 3x {}^{3} + x {}^{2} - 8x + 1 - x {}^{3} + 8x {}^{2} - 7x + 1$

$= > a = 2x {}^{3} + 9x {}^{2} - 15x + 2$