Question

math 7 fa 11 simplifying expressions quiz review
directions: answer the following questions using the key provided.
key: □ = 1 ■ = -1 ▭ = x ▬ = -x

1. which model below represents the expression $3x - 4?$

a)
b)
c)
d)

Explanation:

Step1: Break down the target expression

The expression $3x - 4$ can be rewritten as $3x + (-4)$.

Step2: Match to the key symbols

• $3x$ corresponds to 3 white rectangles (since $\square_{\text{long}} = x$)
• $-4$ corresponds to 4 black squares (since $\blacksquare = -1$, so $4 \times -1 = -4$)

Step3: Evaluate each option

• a) 3 white rectangles + 4 white squares = $3x + 4$
• b) 3 black rectangles + 4 white squares = $-3x + 4$
• c) 3 white rectangles + 4 black squares = $3x - 4$
• d) 3 white squares + 4 black rectangles = $3 - 4x$

Answer:

c) <the model with 3 white rectangles and 4 black squares>