Given: where , , , , are unique positive single-digit numbers, what is the number of possible combinations for and to satisfy this equation?

Step-by-step explanation:

Sum of two digits can be less than 20, therefore A = 1 is the only option for A, since AB ≤ 19.

Substitute A:

Then Y = 0 or Y = 5.

Y = 0 doesn't work as it leads to B = 1, which is a repeat of A.

So Y = 5.

Substitute Y:

We see B = 2 is the only option for B, since X + Z = 11, add 1 to 1 (5 + 5 gives us 1 for 10).

Substitute B:

Possible options for X and Z:

answer: 590

step-by-step explanation:

the 2 figures are congruent bc if you reflect abcd over the y axis then over the d axis the figures overlap