1. **Problem:** Solve the system graphically for part (a):
$$y = -3x + 9$$
$$3y - 3x = 3$$
2. **Rewrite the second equation in slope-intercept form:**
$$3y - 3x = 3 \implies 3y = 3x + 3 \implies y = \frac{3x + 3}{3} = x + 1$$
3. **Plot both lines:**
- Line 1: $y = -3x + 9$
- Line 2: $y = x + 1$
4. **Find the point of intersection (POI) algebraically:**
Set $-3x + 9 = x + 1$
$$-3x + 9 = x + 1$$
$$-3x - x = 1 - 9$$
$$-4x = -8$$
$$x = \frac{\cancel{-8}}{\cancel{-4}} = 2$$
Substitute $x=2$ into $y = x + 1$:
$$y = 2 + 1 = 3$$
POI is $(2, 3)$.
---
1. **Problem:** Solve the system graphically for part (b):
$$y = -2x + 4$$
$$3y - 2x + 12 = 0$$
2. **Rewrite the second equation in slope-intercept form:**
$$3y - 2x + 12 = 0 \implies 3y = 2x - 12 \implies y = \frac{2x - 12}{3} = \frac{2}{3}x - 4$$
3. **Plot both lines:**
- Line 1: $y = -2x + 4$
- Line 2: $y = \frac{2}{3}x - 4$
4. **Find the POI algebraically:**
Set $-2x + 4 = \frac{2}{3}x - 4$
Multiply both sides by 3 to clear denominator:
$$3(-2x + 4) = 3\left(\frac{2}{3}x - 4\right)$$
$$-6x + 12 = 2x - 12$$
Bring terms to one side:
$$-6x - 2x = -12 - 12$$
$$-8x = -24$$
$$x = \frac{\cancel{-24}}{\cancel{-8}} = 3$$
Substitute $x=3$ into $y = -2x + 4$:
$$y = -2(3) + 4 = -6 + 4 = -2$$
POI is $(3, -2)$.
---
1. **Problem:** Solve the system graphically for part (c):
$$4y + 4 = -3x$$
$$3y + 9x + 3 = 0$$
2. **Rewrite both equations in slope-intercept form:**
First equation:
$$4y + 4 = -3x \implies 4y = -3x - 4 \implies y = \frac{-3x - 4}{4} = -\frac{3}{4}x - 1$$
Second equation:
$$3y + 9x + 3 = 0 \implies 3y = -9x - 3 \implies y = \frac{-9x - 3}{3} = -3x - 1$$
3. **Plot both lines:**
- Line 1: $y = -\frac{3}{4}x - 1$
- Line 2: $y = -3x - 1$
4. **Find the POI algebraically:**
Set $-\frac{3}{4}x - 1 = -3x - 1$
Add 1 to both sides:
$$-\frac{3}{4}x = -3x$$
Multiply both sides by 4 to clear denominator:
$$-3x = -12x$$
Add $12x$ to both sides:
$$-3x + 12x = 0 \implies 9x = 0 \implies x = 0$$
Substitute $x=0$ into $y = -3x - 1$:
$$y = -3(0) - 1 = -1$$
POI is $(0, -1)$.
---
**Final answers:**
- (a) POI: $(2, 3)$
- (b) POI: $(3, -2)$
- (c) POI: $(0, -1)$
Linear Systems Graphical A90Cba
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.