Question

Find the value of x and y for the equation x+y5 7x+9y=6

Answer 1

Answer:

$x = \frac{39}{2}$

$y = -\frac{29}{2}$

Step-by-step explanation:

Given

$x + y= 5$ --- (1)

$7x + 9y = 6$ ---- (2)

Required

Find x and y

Make x the subject in (1)

$x + y= 5$

$x = 5 - y$

Substitute 5- y for x in (2)

$7x + 9y = 6$

$7(5 - y) + 9y = 6$

Open bracket

$35 -7 y + 9y = 6$

Collect like terms

$-7y + 9y = 6 - 35$

$2y = -29$

Divide both sides by 2

$y = -\frac{29}{2}$

Substitute this for y in $x = 5 - y$

$x = 5 - (-\frac{29}{2})$

$x = 5 +\frac{29}{2}$

L.C.M

$x =\frac{10+29}{2}$

$x = \frac{39}{2}$