Let’s solve each problem one by one.
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Problem 1:
We are given a graph of a line and need to write its equation in slope-intercept form:
>
y = mx + b, where m is the slope, and b is the y-intercept.
From the graph:
- The line crosses the y-axis at
(0, -2) → so
b = -2
- To find slope (m), pick two points on the line. Let’s use:
- Point A: (0, -2)
- Point B: (-5, 5) — looks like it passes through there? Wait, let me check again.
Actually, looking carefully:
At x = 0, y = -2 → that’s clear.
At x = -5, y = 5? Let’s count grid units.
From (0, -2) going left 5 units (to x = -5), we go up 7 units → to y = 5. So yes, point (-5, 5) is on the line.
So slope m = rise/run = (5 - (-2)) / (-5 - 0) = 7 / (-5) =
-7/5
So equation:
y = (-7/5)x - 2
That matches option
C
✔ Check: Plug in x=0 → y=-2 ✔️
Plug in x=-5 → y = (-7/5)(-5) - 2 = 7 - 2 = 5 ✔️
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Problem 2:
Graph shows a line with positive slope.
Y-intercept: crosses y-axis at
(0, 4) → so
b = 4
Find another point: when x = 3, y = 6? Let’s see.
From (0,4) to (3,6): rise = 2, run = 3 → slope = 2/3
Equation:
y = (2/3)x + 4
That’s option
C
✔ Check: x=0 → y=4 ✔️
x=3 → y=(2/3)*3 + 4 = 2+4=6 ✔️
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Problem 3:
“through: (2, 4), parallel to y = 3x - 3”
Parallel lines have same slope.
Slope of given line:
m = 3
Point-slope form:
y - y₁ = m(x - x₁)
Plug in: y - 4 = 3(x - 2)
That’s option
B
✔ Correct.
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Problem 4:
“through: (1, -4), parallel to x = 0”
x = 0 is the
y-axis — a vertical line.
A line parallel to a vertical line is also
vertical.
Vertical line through (1, -4) has equation:
x = 1
But none of the options say x = 1 directly.
Look at options:
A) y + 4 = -3(x + 1) → not vertical
B) y + 1 = 3(x + 4) → not vertical
C) 0 = x - 1 → which means
x = 1 ← this is correct!
D) y + 4 = 0 → horizontal line y = -4
So answer is
C
✔ Because 0 = x - 1 → x = 1
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Problem 5:
“through: (-5, -4), perp. to y = -5/6 x - 3”
Perpendicular slopes are negative reciprocals.
Given slope: m = -5/6
Negative reciprocal: flip fraction and change sign →
6/5
Point-slope form using point (-5, -4):
y - (-4) = (6/5)(x - (-5))
→ y + 4 = (6/5)(x + 5)
That’s option
D
✔ Check: slope is 6/5, point (-5,-4) plugged in correctly.
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Problem 6:
“through: (5, -5), perp. to y = 5/8 x - 3”
Given slope: 5/8
Perpendicular slope: negative reciprocal →
-8/5
Point-slope form using (5, -5):
y - (-5) = (-8/5)(x - 5)
→ y + 5 = (-8/5)(x - 5)
That’s option
C
✔ Correct.
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Final Answers:
1) C
2) C
3) B
4) C
5) D
6) C
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Final Answer:
1) C
2) C
3) B
4) C
5) D
6) C
Parent Tip: Review the logic above to help your child master the concept of writing an equation of a line worksheet.