(i)2x+y=7
⇒y=7−2x
→ Put x=0,
y=7−2×0⇒y=7
(0,7) is a solution.
→ Now, put x=1
y=7−2×1⇒y=5
(1,5) is a solution.
→ Now, put x=2
y=7−2×2⇒y=3
(2,3) is a solution.
→ Now, put x=−1
y=7−2×−1⇒y=9
(−1,9) is a solution.
(ii)πx+y=9
⇒y=9−πx
→ Put x=0,
y=9−π×0⇒y=9
(0,9) is a solution.
→ Now, put x=1
y=9−π×1⇒y=9−π
(1,9−π) is a solution.
→ Now, put x=2
y=9−π×2⇒y=9−2π
(2,9−2π) is a solution.
→ Now, put x =−1
y=9−π×−1⇒y=9+π
(−1,9+π) is a solution.
(iii)x=4y
→ Put x=0,
0=4y
⇒y=0
(0,0) is a solution.
→ Now, put y=1
x=4(1)⇒4
(4,1) is a solution.
→ Now, put y=−1
x=4(−1)
x=−4
Therefore, (−4,−1) is a solution of this equation.
For x=2,
2=4y
y=24=12
Therefore, (2,12) is a solution of this equation.