SAT · Math —

Heart of Algebra appeared 17 times across 1 year — 100% of Math. This question is from Linear Equations and Inequalities.

Year 2023 Total
Questions 17 17

Which of the following graphs demonstrates a system of linear equations with no solution? i.
Linear Equations and Inequalities diagram for Q8 - SAT 2023
Four distinct coordinate sub-graphs labeled i, ii, iii, iv showing different line pairs.
ii.
Linear Equations and Inequalities diagram for Q8 - SAT 2023
Four distinct coordinate sub-graphs labeled i, ii, iii, iv showing different line pairs.
iii.
Linear Equations and Inequalities diagram for Q8 - SAT 2023
Four distinct coordinate sub-graphs labeled i, ii, iii, iv showing different line pairs.
iv.
Linear Equations and Inequalities diagram for Q8 - SAT 2023
Four distinct coordinate sub-graphs labeled i, ii, iii, iv showing different line pairs.

Linear Equations and Inequalities diagram for Q8 - SAT 2023
Four distinct coordinate sub-graphs labeled i, ii, iii, iv showing different line pairs.

Solution & Explanation

Related Formula

A system of linear equations has no solution if and only if the lines are parallel.

Core Logic

Examine each graph for parallel lines:

  • Graph i shows perpendicular lines (one vertical, one horizontal).
  • Graph ii shows two horizontal parallel lines.
  • Graph iii shows two vertical parallel lines.
  • Graph iv shows intersecting lines.
Step 1: Conclusion

Since graphs ii and iii depict parallel lines, both systems have no solution. Hence, option D is correct.

Pattern Recognition

Identify parallel orientation in multi-graph sets arrow both represent no solution systems.

Chapter Mix

SAT Math: Heart of Algebra

More Heart of Algebra Previous-Year Questions — Page 2

Q sat_math_2023_01_january_morning Linear Equations and Inequalities
The following graphs represent a system of linear equations. The lines shown are parallel. How many solutions will this system of equations have?
Linear Equations and Inequalities diagram for Q7 - SAT 2023
A graph showing two parallel lines that never intersect.
  • A. No solution
  • B. One solution
  • C. Infinite solutions
  • D. Because we are not given the equations of the lines, it is impossible to know.

Solution

Related Formula

Parallel lines have the same slope (m₁ = m₂) but different y-intercepts (b₁ ≠ b₂).

Core Logic

Parallel lines never cross or intersect at any point in the plane.

Since the solution of a system is defined as the set of all intersection points, parallel lines yield zero intersection points.

Step 1: Conclusion

Therefore, the system has no solution.

Pattern Recognition

Parallel lines arrow zero intersections arrow no solution.

Chapter Mix

SAT Math: Heart of Algebra

Q sat_math_2023_01_january_morning Systems of Linear Inequalities
A man buys a apples and g oranges, each costing 80 cents and 60 cents respectively. If the man buys less than 18 fruits and spends less than $12, which of the following is the correct inequality representing the above information?
  • A. a + g = 18 4a + 3g = 60
  • B. a + g < 18 4a + 3g < 60
  • C. a + g ≤ 18 4a + 3g ≤ 60
  • D. a + g ≤ 18 4a + 3g = 60

Solution

Related Formula
Total Cost (cents) = 80a + 60g < 1200

since 12 = 1200cents.

Core Logic

Fruit quantity condition: buys 'less than 18 fruits'

Core Logic

Fruit quantity condition: buys 'less than 18 fruits' $\rightarrow a + g < 18.

Cost condition: spends 'less than

Cost condition: spends 'less than $\12' arrow 80a + 60g < 1200.

Simplify the cost inequality by dividing all terms by 20:

(80a)/(20) + (60g)/(20) < (1200)/(20) 4a + 3g < 60
Step 1: Conclusion

The system of inequalities is a + g < 18 and 4a + 3g < 60 (Option B).

Pattern Recognition

'Less than' strictly means <, not ≤. Convert dollars to cents before simplifying.

Chapter Mix

SAT Math: Heart of Algebra

Q5 sat_math_2023_01_january_morning Systems of Linear Inequalities
Samantha bought M&Ms from the store. She is told that the amount of sweet M&Ms and the amount of bitter M&Ms is represented by the following system of inequalities, where s is the number of sweet M&Ms and b is the number of bitter M&Ms: s + b ≥ 25 5s - 10b < 2 Which of the following solutions, in the format (s, b) could be a possible solution for the number of M&Ms in Samantha's bag?
  • A. (6, 10)
  • B. (2, 30)
  • C. (1, 1)
  • D. (50, 10)

Solution

Related Formula

For a coordinate pair (s, b) to be a valid solution to a system of inequalities, it must satisfy all given inequalities simultaneously.

Core Logic

Test the ordered pair (2, 30) where s = 2 and b = 30:

First inequality:

2 + 30 = 32 ≥ 25 (True)

Second inequality:

5(2) - 10(30) = 10 - 300 = -290 < 2 (True)
Step 1: Conclusion

Since both statements evaluate to true for (2, 30), option B is a valid solution.

Pattern Recognition

System of inequalities question arrow plug and check given options to find which makes both true.

Chapter Mix

SAT Math: Heart of Algebra

Q9 sat_math_2023_01_january_morning Solving Linear Equations
If a + 2b + 3c = 24 and 3a + 2b + c = 36, what is the value of (a + b + c)?
  • A. 8
  • B. 12
  • C. 15
  • D. 60

Solution

Related Formula

For symmetric linear systems, adding equations directly often isolates the required expression (a + b + c) without solving for individual variables.

Core Logic

Given equations:

a + 2b + 3c = 24 (1) 3a + 2b + c = 36 (2)

Add (1) and (2) together:

(a + 3a) + (2b + 2b) + (3c + c) = 24 + 36 4a + 4b + 4c = 60
Step 1: Solve for (a + b + c)

Factor out 4:

4(a + b + c) = 60

Divide by 4: a + b + c = 15

Thus, the correct answer is C.

Pattern Recognition

Symmetric coefficients arrow add equations directly to avoid tedious multi-variable elimination.

Chapter Mix

SAT Math: Heart of Algebra

More Heart of Algebra Questions — sat_math_2023_01_january_morning

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JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%) | JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%)