Question

drag the red and blue dots along the x-axis and y-axis to graph $-7x + 7y = 28$.

Explanation:

Step1: Find y-intercept (x=0)

Substitute \( x = 0 \) into \( -7x + 7y = 28 \):
\( -7(0) + 7y = 28 \)
\( 7y = 28 \)
\( y = 4 \). So y-intercept is \( (0, 4) \).

Step2: Find x-intercept (y=0)

Substitute \( y = 0 \) into \( -7x + 7y = 28 \):
\( -7x + 7(0) = 28 \)
\( -7x = 28 \)
\( x = -4 \). Wait, the graph’s red dot is at \( x=5 \), which is wrong. Wait, recalculate:
Wait, original equation: \( -7x + 7y = 28 \). Divide both sides by 7: \( -x + y = 4 \), so \( y = x + 4 \).
For x-intercept (y=0): \( 0 = x + 4 \) → \( x = -4 \). So x-intercept is \( (-4, 0) \), y-intercept \( (0, 4) \). The graph’s red dot is at \( x=5 \), which is incorrect. To graph correctly, drag red dot (x-intercept) to \( (-4, 0) \) and blue dot (y-intercept) to \( (0, 4) \).

Answer:

To graph \( -7x + 7y = 28 \) (or \( y = x + 4 \)):

• Red dot (x-intercept): Drag to \( (-4, 0) \) (on x-axis, \( x = -4 \), \( y = 0 \)).
• Blue dot (y-intercept): Drag to \( (0, 4) \) (on y-axis, \( x = 0 \), \( y = 4 \)).