Processing math: 62%
Home / Aptitude Tests / Mathematics / Determine x + y if \...
Determine x + y if \(\begin{pmatrix} 2 & -3 \\ -1 & ...

Determine x + y if (2314) (xy) = (18)

A.

3

B.

4

C.

7

D.

12

Correct answer is C

(2314)(xy)=(18)

(2x3yx+4y)=(18)

2x3y=1...(i)

x+4y=8...(ii)

From (ii), x = 4y - 8.

2(4y8)3y=18y163y=1

5y=1+16=15y=3

x=4(3)8=128=4