Question

If x = a, y = b is the solution of the pair of equations x – y = 2 and x + y = 4,then the respective values of a and b are: (a) 3, 5 (b) 5, 3 (c) 3, 1 (d) -1, -3

Answer 1

$\bold{GIVEN:}$

★$x=a$

$y=b$

★the equation:

✏ $x-y=2$

✏ $x+y=4$

sub $x=a,y=b$ in the equation.

✏ $a-b=2$ -------᚛❶

✏ $a+b=4$ -------᚛❷

$\bold{SOLVE:}$

From equation ❶ and ❷

$a-b=2$

$a+b=4$

$2a=6$

$a=\frac{6}{2}$

$\boxed{a=3}$

sub $a=3$ in ❷

$a+b=4$ -------᚛❷

$3+b=4$

$b=4-3$

$\boxed{b=1}$