Question

Solve the following pair of equation by the substitution method
$x+y=4$ and $2x+y=3$

• A. -1 and 5
• B. 1 and -5
• C. 1 and 5
• D. -1 and -5

Answer 1

Answer: (A)

-1 and 5

$x+y=4$ ------- (1)
$2x+y=3$ ------ (2)
From equation 1:
$y=4x$
Substitute the value of y in equation 2:
$2x+4x=3$
$X=34$
$X=-1$
Now, Substitute $x=-1$ in equation 1:
$-1+y=4$
$y=4+1$
$y=5$
Therefore the solution is $x=-1$ and $y=5$