Question

x = 5, y = 2 is a solution of the linear equation

(a) x + 2y = 7

(b) 5x + 2y = 7

(c) x + y = 7

(d) 5x + y = 7

Answer 1

Substituting the values x = 5, y = 2 in

(a) $x+2y=7$, we get

$LHS=5+2\times 2=5+4=9\ne 7=RHSi.e.LHS\ne RHS$

(b) $5x+2y=7$, we get

$LHS=5\times 5+2\times 2=25+4=29\ne 7=RHSi.e.LHS\ne RHS$

(c) $x+y=7$, we get

$LHS=5+2=7=RHSi.e.LHS=RHS$

(d) $5x+y=7$, we get

$LHS=5\times 5+2=25+2=27\ne 7=RHSi.e.LHS\ne RHS$

Hence, the correct option is (c).