The only correct answer is C.) 9
✓16 = 4
5+4= 9
x = 9
The first one because it is right
Answer: Correct two digit number= 24
Step-by-step explanation:
Let
x= tens digit (wrong one)
and y= zeroes digit
and z= tens digit (right one)
Now according to the statement,
(10x+y)² - (10z+y)² = 2340
Simplifying this we get
(x-z)(5x+y+5z)= 117= 1 * 3 * 3 * 13
So it could either be
x-z=1 or x-z=3
If we take the x-z=1
then 5x+y+5z=117
which is not possible as maximum value we can get from this is 99.
This leaves us with x-z=3
so 5x+y+5z= 39
Put x=3+z
We get,
y+10z= 24
Now as y and z both are single digits so the only possible numbers to fit these are y=4 and z=2.
Put z=2 in x=3+z , we get x=5
So the numbers become 10x+y= 54
and 10z+y= 24
Their sum is 54+24=78
Check
54²-24²= 2340 so it is correct.
Triangles ABC and DEF may or may not be congruent, because the angle-angle-angle (AAA) postulate is not a criterion for congruency of any two triangles. This is because the angle-angle-angle postulate only incorporates the angles of the triangles, and the side lengths are not specified, so congruency may or may not be true for these triangles.
