Question

The sum of two number is 7 and their difference is 1. Find the numbers.

• A. 4 and 3
• B. 2 and 3
• C. -4 and 3
• D. 4 and -3

Answer 1

The correct option is A 4 and 3

Let the two numbers be $x$ and $y$.
$x+y=7$ ----- (1)
$x-y=1$ ----- (2)
Adding equation (1) and (2), we get
$x+y=7$
$x-y=1$
_________
$2x=8$
$x=\frac{8}{2}=4$
Substituting the value $x$ in equation (1), we get
$4+y=7$
$y=7-4$
$y=3$
Therefore, $x=4$ and $y=3$
Hence, the two numbers are $4$ and $3$.