The text book store sold a combined total of 326 history and chemistry textbooks in a week. The number of chemistry textbooks sold was 86 less than the number of history textbooks sold. How many textbooks of each type was sold?

The sentence

"The Number of Chem textbooks sold is 86 less than the number of History textbooks"

This seems to be the confusing part.

Now look at it this way...

'If CHM text is 86 less than History text... It also means that History Text is 86 More than CHM'

This expression can be written as

Let History Text be "H"

Let CHM text be "C"

C - 86 = H

or

C=H + 861

First line of this question is interpreted thus

H + C = 3262

From eqn 1... C=H+86

Substitute into Eqn 2

H + C=326

H + (H+86)=326

H+H=326-86

2H=240

H=240/2

H=120.

C=H+86

C=120+86

C=206.

This answer is correct... Why?

The key statement says .. The Number of CHM sold is 86 less than History...

Also interpreted as

The Number of CHM – 86 = History

206 - 86 =120.

Have a great day!!!

first, we define the variables:

x: number of years after 1950

f (x): amount of vinyl sold.

then, with the variables defined, we have:

68594 vinyl records were sold in 1958 > f (8) = 68594

91299 vinyl records were sold in 1961 > f (11) = 91299

38720 vinyl records were sold in 1952 > f (2) = 38720

161743 vinyl records were sold in 1967 > f (17) = 161743

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step-by-step explanation: