10x+y=4(x + y)=x ×y+16
10x+y=4x+4y
6x=3y
2x=y
10x+2x=xy+16
12x=2x^2+16
taking 2 common we get
2(x^2-6x+8)
2(x^2-4x-2x+8)
2[(x-4)(x-2)] by comparing
therefore, the no. is x is 8 and y is 4
84 or 48 ,lets compare with .1
10×4+8=4(4+8)
hence the required no. is 48.