7. which equation best represents the relationship between x and y in the graph? a. y = 3x - 2 b. y =…

7. which equation best represents the relationship between x and y in the graph? a. y = 3x - 2 b. y = -\\frac{1}{2}x + 3 c. y = -2x + 3 d. y = 2x + \\frac{3}{2}

7. which equation best represents the relationship between x and y in the graph? a. y = 3x - 2 b. y = -\\frac{1}{2}x + 3 c. y = -2x + 3 d. y = 2x + \\frac{3}{2}

Answer

Explanation:

Step1: Find the slope ($m$)

The slope formula is $m=\frac{y_2 - y_1}{x_2 - x_1}$. Let's take two points from the graph, say $(0,-2)$ and $(2,1)$. $m=\frac{1-(-2)}{2 - 0}=\frac{3}{2}$.

Step2: Find the y - intercept ($b$)

The y - intercept is the value of $y$ when $x = 0$. From the point $(0,-2)$, $b=-2$.

Step3: Use the slope - intercept form $y=mx + b$

Substitute $m=\frac{1}{2}$ and $b=-2$ into $y = mx + b$. We get $y=\frac{1}{2}x-2$. Wait, no, let's check the points again. Wait, another approach: check each option. For option A: $y = 3x-2$, when $x = 0$, $y=-2$ (correct y - intercept). When $x = 1$, $y=3\times1 - 2=1$. But from the graph, when $x = 1$, if we assume the slope is wrong. Wait, let's use the general form $y=mx + b$. Take two points: Let’s assume two clear points. Suppose the line passes through $(4,0)$ and $(0,-2)$. Slope $m=\frac{0-(-2)}{4-0}=\frac{2}{4}=\frac{1}{2}$. But wait, no, wait the options. Wait, no, wait, another way: The equation of a line in slope - intercept form is $y=mx + b$, where $m$ is the slope and $b$ is the y - intercept. The y - intercept ($b$) is the value of $y$ when $x = 0$. From the graph, when $x = 0$, $y=-2$, so $b=-2$. Now check the slope for each option:

  • Option A: $y = 3x-2$, slope $m = 3$.
  • Option B: $y=-\frac{1}{2}x + 3$, slope $m=-\frac{1}{2}$, y - intercept $b = 3$.
  • Option C: $y=-2x + 3$, slope $m=-2$, y - intercept $b = 3$.
  • Option D: $y=\frac{1}{2}x-2$, slope $m=\frac{1}{2}$, y - intercept $b=-2$. Wait, no, wait the original options: Wait, the user might have a typo. Wait, re - check the graph. If we assume two points: say $(4,0)$ and $(0,-2)$ Slope $m=\frac{0-(-2)}{4-0}=\frac{1}{2}$. But there is no $y=\frac{1}{2}x-2$ in options. Wait, no, wait the options: Wait, looking at the options again: Option A: $y = 3x-2$ Option B: $y=-\frac{1}{2}x + 3$ Option C: $y=-2x + 3$ Option D: $y=\frac{1}{2}x+\frac{3}{2}$ (Wait, no, original options: A. $y = 3x-2$ B. $y=-\frac{1}{2}x + 3$ C. $y=-2x + 3$ D. $y=\frac{1}{2}x+\frac{3}{2}$ Wait, no, re - check the graph. Let’s use the two - point formula correctly. Suppose two points: $( - 2,-3)$ and $(2,-1)$ Slope $m=\frac{-1-(-3)}{2-(-2)}=\frac{2}{4}=\frac{1}{2}$ Using point - slope form $y - y_1=m(x - x_1)$, take $(x_1,y_1)=(0,-2)$ (since when $x = 0,y=-2$) $y-(-2)=\frac{1}{2}(x - 0)$ $y=\frac{1}{2}x-2$ but this is not in options. Wait, no, maybe misread the graph. Wait, another approach: substitute $x = 0$ into each equation:
  • Option A: $y=3\times0-2=-2$
  • Option B: $y=-\frac{1}{2}\times0 + 3=3$
  • Option C: $y=-2\times0+3=3$
  • Option D: $y=\frac{1}{2}\times0+\frac{3}{2}=\frac{3}{2}$ Since when $x = 0$, from the graph $y=-2$, only option A has $y=-2$ when $x = 0$. Now check another point. Let’s take $x = 1$ Option A: $y=3\times1-2=1$ If we assume a point $(1,1)$ is on the line (by visual inspection of the graph, if the scale is 1 unit per grid).

Answer:

A. $y = 3x-2$