In the equation y = 3x + 7, what is the slope?
- 3
- 7
- 10
- 21
Show answer and explanation
Answer: 3
In y = mx + b, m is the slope. Here m = 3.
SAT Math skill page
Read y = mx + b as a story about starting value and rate of change.
What this tests
Practice examples
In the equation y = 3x + 7, what is the slope?
Answer: 3
In y = mx + b, m is the slope. Here m = 3.
A line has slope -2 and y-intercept 5. Which equation represents the line?
Answer: y = -2x + 5
Use y = mx + b with m = -2 and b = 5.
A gym charges $20 to join and $15 per month. Which equation gives total cost C after m months?
Answer: C = 15m + 20
The monthly rate is the slope, 15, and the initial fee is the intercept, 20.
Quick drills
Pause before the answer choices, write the rule or setup you need, then check whether the question is asking for the value, the relationship, or the best-supported conclusion.
Pause before the answer choices, write the rule or setup you need, then check whether the question is asking for the value, the relationship, or the best-supported conclusion.
Pause before the answer choices, write the rule or setup you need, then check whether the question is asking for the value, the relationship, or the best-supported conclusion.
Pause before the answer choices, write the rule or setup you need, then check whether the question is asking for the value, the relationship, or the best-supported conclusion.
Avoid these traps
The SAT often hides the real skill inside familiar wording. Identify the rule, relationship, or question type first.
Many wrong answers are close. Check every condition in the question before committing.
Reread what the question asks for so you do not answer a nearby but different question.
Study plan
Related practice
Skill cluster
FAQ
Start with a few focused examples, review the mistake pattern, then mix the skill into full SAT practice so you can recognize it in context.
It shows up in short, high-leverage questions where one missed rule or setup can quickly cost a point.
Yes. Dolphin SAT can surface targeted practice, track missed questions, and help you review the patterns that keep repeating.