Question

Solve for x and y for the following pair of lines
x + y = 42
0.24x + 0.18y = 8.4

• A. x = 10, y = 32
• B. x = 14, y = 28
• C. x = 16, y = 34
• D. x = 17, y = 25

Answer 1

The correct option is B

x = 14, y = 28

$x+y=42$ _______(1)
$0.24x+0.18y=8.4$ ___(2)
From equation (1),
$x=42-y$ _______(3)
Substituting the value of x in equation (2)
$0.24(42-y)+0.18y=8.4$
$10.08-0.24y+0.18y=8.4$
$10.08-0.06y=8.4$
$-0.06y=-1.68$
$y=28$
Substituting the value of y in equation (3)
$x=42-28$
$x=14$