Question

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. $5x+2y=7$

Answer 1

The correct option is C $x+y=7$

Let us consider x + 2y, on substituting 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.

Now, let us consider 5x + 2y, on substituting 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.

Let us consider x + y, on substituting x = 5 and y = 2, we get 5 + 2 = 7.
So, (5, 2 ) is a solution of x + y = 7.

Let us consider 5x + y, on substituting 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.