Question

A person buys X meter for 5

Answer 1

Step-by-step explanation:

I guess, it means every meter costs these amounts.

and the specified costs are not fit the whole bundle.

it is also unclear, if "half of it" means half of the original x meters, or half of the remaining meters (after selling 2/5 of the original meters). I assume the first.

so, we have

-5x

+ 2/5x × 5.5

+ 1/2x × 6.4

+ (10/10 - 4/10 - 5/10)x × 6 = + 1/10x × 6

= 120 ( a income minus costs is the profit, so balancing both sides in a "+" and "-" expression gives us the remaining profit).

about the line with the 1/10 :

the leftovers. 10/10 is the whole x at the beginning.

2/5 = 4/10.

1/2 = 5/10.

I brought all involved fractions to the same denominator of the smallest common multiple of 2 and 5 (10).

in full

-5x + (2/5)x×5.5 + (1/2)x×6.4 + (1/10)x×6 = 120

-5x + 2.2x + 3.2x + 0.6x = 120

-5x + 6x = 120

x = 120

so, he bought 120m in the first place.