Question

what us the answer of the question​

Answer 1

Answer:

The number is 87 or -78.

Step-by-step explanation:

Let the two-digit number be 10x + y.

It is provided that

$x\times y=56...(i)\\10x+y-9=10y+x...(ii)$

Solve (i) for x as follows:

$x\times y=56\\x=\frac{56}{y}$

Solve (ii):

$10x + y - 9 = 10y + x\\9x - 9y = 9\\x - y = 9...(iii)$

Substitute the value of x in the (iii) equation as follows:

$x-y=1\\\frac{56}{y} -y=1\\\\56-y^{2}=y\\y^{2}+y-56=0\\y^{2} + 8y-7y-56=0\\y(y+8)-7(y+8)=0\\(y+8)(y-7)=0$

For y - 7 = 0 the value of y is 7.

Compute x as follows:

$x=\frac{56}{7}=8$

For y + 8 = 0 the value of y is -8.

Compute x as follows:

$x=\frac{56}{-8}=-7$

Thus, the number is 87 or -78.