bearing in mind that standard form for a linear equation means
• all coefficients must be integers, no fractions
• only the constant on the right-hand-side
• all variables on the left-hand-side, sorted
• "x" must not have a negative coefficient


quick note:
the "x" must not have a negative coefficient for the standard form, though in this case it shows like so in the inappropriate choices above.
Given that : Tom bought total = 47 jigsaw puzzles.
Number of pieces in each puzzle = 70 pieces.
We need to find the number of pieces in all 47 jigsaw puzzles.
<em>In order to find the number of pieces in all 47 jigsaw puzzles, we need to multiply 47 jigsaw puzzles by 70 pieces each.</em>
We get
47 × 70 = 3290 pieces.
<h2>Therefore, Tom got total 3290 pieces all in 47 jigsaw puzzles.</h2>