Question

Question 11
x = 5 and 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

The answer is C.
(a) Take x + 2y, on putting x = 5 and y = 2, we get;
5 + 2(2) = 5 + 4 = 9 $\ne$ 7
So, (5, 2) is not a solution of x+2y=7.
(b) Take 5x + 2y, on putting x = 5 and y = 2; we get,
$5\times 5+2\times 2=25+4=29\ne 7$
So, (5, 2) is not a solution of 5x + 2y = 7.
(c) Take x + y, on putting x = 5 and y = 2, we get 5 + 2 = 7.
So, (5 ,2 ) is a solution of x + y = 7
(d) Take 5x + y, on putting x = 5 and y =2, we get;
$5\times 5+2=25+2=27\ne 7$
So,(5, 2) is not a solution of 5x + y = 7.