The sum of the two digits of a number is 16.The number formed by reversing the digits is 18 more than the original number. Find the original number and its reversal

97 and 79

Why:

Every number has a ones place digit, tens place digit, hundreds place digit, so on and so forth.

We are looking at a 2 digit number so let’s say that the tens place digit is “a” and the ones place digit is “b”.

Now I’m going to write out what we know using these variables.

a + b = 16

And 10*a + b = 10b + a + 18

Now you have two unknowns and two equations and you just solve for a or b. Then plug in a to get b in a+b = 16. Or viceversa.

something that characterises a right triangle is the fact that we may use pythagoras' theorem to find any one of its sides given that we have the length of the other two sides. here, we have the length of the hypotenuse, √(87) yd, and one other side, √(23) yd, thus we can easily find the length of the remaining side using pythagoras' theorem as defined below:

c^2 = a^2 + b^2, where c is the length of the hypotenuse, and a and b are the lengths of the other two sides.

thus, given that c = √(87) and a = √(23), we may substitute these into the formula we defined above to get:

c^2 = a^2 + b^2

(√87)^2 = (√23)^2 + b^2 (substitute c = √87 and a = √23 into the equation)

87 = 23 + b^2 (evaluate (√87)^2 = 87 and (√23)^2 = 23 - remember that the square root of a number, squared will equal that very same number)

64 = b^2 (subtract 23 from both sides)

√64 = b (take the square root of both sides)

8 = b (evaluate √64 = 8)

therefor, the length of the unknown leg in the right triangle is 8 yd (first answer).