- A
- B
- C
- D
Step-by-Step Solution
Sonia’s age = brother’s age + 3, so , i.e. would make the brother the older one, and adds their ages instead of comparing them.)
Answer: B)
Sonia is 3 years older than her brother. Taking Sonia’s age as years and her brother’s age as years, which equation models this?
Class 9Linear Equations in Two VariablesLinear Equations
Key idea: Finding solutions to a linear equation
Pick any value for one variable; solve for the other. Repeat to get many solutions.
Example: .
- Let → . So (0, 6) is a solution (this is the -intercept).
- Let → . So (2, 3) is a solution.
- Let → . So (4, 0) is a solution (this is the -intercept).
- Let → . Same as above.
Four solutions found in seconds, and infinitely more available.
Example: .
- Let → . So (0, 6) is a solution (this is the -intercept).
- Let → . So (2, 3) is a solution.
- Let → . So (4, 0) is a solution (this is the -intercept).
- Let → . Same as above.
Four solutions found in seconds, and infinitely more available.
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