Home › EQAO Grade 9 Math › Mathematics › Systems of Linear Equations in Two Variables › Check the pair x = 4, y = 3 against this system:…
Check the pair x = 4, y = 3 against this system: 2x + 5y = 23 and 3x - y = 9.
AIt is the solution, since both come out true
BIt fails, since only the first comes out true
CIt fails, since only the second comes out true
DIt fails, since neither one comes out true
Answer & Solution
Correct answer: A. It is the solution, since both come out true
1. Put x = 4 and y = 3 into the first rule: 2 times 4 is 8, and 5 times 3 is 15.
2. Adding gives 8 plus 15, which is 23, and the first rule asked for 23, so it holds.
3. Put the same pair into the second rule: 3 times 4 is 12, and 12 minus 3 is 9.
4. The second rule asked for 9, so it holds as well.
5. A pair that satisfies both rules is the solution, option A.
_Source: OpenStax College Algebra (CC BY 4.0), Ch 7 "Systems of Equations and Inequalities", section 7.1 Systems of Linear Equations: Two Variables_
Related questions
Solve this system by adding the rules: 4x + y = 19 and 4x - 3y = 7.One rule of a system reads 2x + 6y = 10 and the other reads x + 3y = 5. What kind of systeCan a system of two linear rules in two unknowns have exactly two solutions?How many rules are needed at the very least before a system in two unknowns can have a sinA pair of values has been worked out for a system. What is the safest way to be sure it isOne rule in a system contains the fractions x over 3 and y over 6. What is the tidiest firIn the system 2x + 3y = 12 and 5x + 4y = 23, which pair of multipliers clears x when the tIn the system x + 3y = 11 and 2x - y = 8, by what number should the first rule be multipli