Question

substitutionmethod x+y=30,x-y=14​

Answer 1

$\bf{x + y = 30} \\ \bf{x - y = 14}$

Taking these as eq (1) & eq (2)

x + y = 30 —————— (1)

x – y = 14 —————— (2)

From eq (1)

$\longrightarrow \: \blue{ \sf{x = 30 - y}}$

Putting (x = 30 – y) in eq (2)

$\longrightarrow \: \sf { x - y = 14}\\ \\ \longrightarrow \: \sf{30 - y - y= 14} \\ \\ \longrightarrow \: \sf{30 - 2y = 14} \\ \\ \longrightarrow \: \sf{ - 2y = 14 - 30} \\ \\ \longrightarrow \: \sf{ \cancel{-} \: 2y = \cancel{-} \: 16} \\ \\ \longrightarrow \: \sf{y = \cancel{\frac{16}{2}} } \\ \\ \longrightarrow \: \fbox{ \red{\sf{y = 8}}}$

Putting the value of y in eq (1)

$\longrightarrow \: \sf{x + y = 30} \\ \\ \longrightarrow \: \sf{x + 8 = 30} \\ \\ \longrightarrow \: \sf{x = 30 - 8} \\ \\ \longrightarrow \: \fbox{ \red{ \sf{x = 22}}}$