Vidaara.orgClass 9 · Mathematics
CodeVID-M09-19-ELM-01
Elimination & Substitution - Assignment
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Section A carries 1 mark each, Section B 2 marks, Section C 3 marks and Section D 5 marks.
- Show all working for Sections B, C and D. Only final answers are given at the end — for full solutions, raise your doubts with your teacher.
Section A — Multiple Choice Questions
5 × 1 = 5 marks
1.
A pair of linear equations in two variables has how many variables?
- A.$1$
- B.$2$
- C.$3$
- D.$4$
2.
In substitution, we express one variable in terms of the:
- A.constant
- B.other variable
- C.coefficient
- D.sum
3.
In elimination, we add or subtract to remove a:
- A.constant
- B.equation
- C.variable
- D.sign
4.
The solution of $x+y=5,\ x-y=1$ is:
- A.$x=3,\ y=2$
- B.$x=2,\ y=3$
- C.$x=4,\ y=1$
- D.$x=1,\ y=4$
5.
A consistent pair of equations has at least one:
- A.variable
- B.solution
- C.constant
- D.graph
Section B — Short Answer (2 marks)
4 × 2 = 8 marks
6.
Solve $x+y=7,\ x-y=3$.
7.
Solve $x+y=10,\ x-y=4$.
8.
Solve $2x=8$.
9.
Solve $x+2y=8$ given $x=2$.
Section C — Short Answer (3 marks)
4 × 3 = 12 marks
10.
Solve $2x+y=7,\ x-y=2$.
11.
Solve $3x+2y=12,\ x+y=5$.
12.
Solve $x+y=9,\ 2x-y=3$.
13.
Solve $5x-2y=4,\ x+2y=8$.
Section D — Long Answer (5 marks)
2 × 5 = 10 marks
14.
Solve by elimination: $3x+4y=10$ and $2x-2y=2$.
15.
Solve by substitution: $2x+3y=13$ and $x-y=-1$.
Answer Key
Section A — Multiple Choice Questions
- (B) $2$
- (B) other variable
- (C) variable
- (A) $x=3,\ y=2$
- (B) solution
Section B — Short Answer (2 marks)
- $x=5,\ y=2$.
- $x=7,\ y=3$.
- $x=4$.
- $y=3$.
Section C — Short Answer (3 marks)
- $x=3,\ y=1$.
- $x=2,\ y=3$.
- $x=4,\ y=5$.
- $x=2,\ y=3$.
Section D — Long Answer (5 marks)
- $x=2,\ y=1$.
- $x=2,\ y=3$.
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