Pls help it’s due very soon and I don’t understand what it’s asking

Which shows one way to determine the factors of  x3  +  5x2  –  6x  –  30 by grouping? x(x2  –  5)  +  6(x2  –  5)x(x2  +  5)  –  6(x2  +  5)x2(x  –  5)  +  6(x  –  5)x2(x  +  5)  –  6(x  +  5)

Find the value of x. round the length to the nearest tenth

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.