Ooh, a puzzle. I like these.
xy=1 AND
x+y=5 ==> y=5-x this step will keep things easier since we will need to substitute
You're going to wind up with a quadratic equation which will give you two numbers.
Substituting, we can have:
y=5-x --> x(5-x)=1 ==> 5x-x2=1 which can be rewritten as
0=x2-5x+1
Boom.
Now to solve this, we go to the quadratic equation. ax2+bx+c
b2-4ac = 25-4(1)(1)=21 I like to solve the inside of the sqrt bracket first
(-b± sqrt (21)) /2a here is the equation with the inside already completed - notice there is a plus/minus sign. there are two equations to be done, one addition, one subtraction.
Since the sqrt(21) is a crazy decimal thing, I won't resolve it into a decimal until the end.
-b+sqrt(21)/2a = 5+sqrt(21)/2
-b-sqrt(21)/2a = 5-sqrt(21)/2
sqrt(21) is approx. 4.583 so we get
5+4.583/2 = 9.583/2 = 4.792 = x
and
5-4.583/2 = .417/2 = .208 = y
Note: the numbers given as x and y are accurate but not 100% because of decimal rounding. This is a good an answer as any and no one should have cause to complain; the answer checks out. :)
-1
-13
-209
-9
-- To add one fifth to a number, add 0.2 to it. -- To find a new number that is one fifth bigger than the original number, multiply the original number by 1.2 .
1 + i and 1 - i, where i is the imaginary number equal to the square root of -1
Let E1 and E2 be two even numbers. Then (E1+1)(E2+1) will be the product of two odd numbers. We have E1*E2 +E2+E1+1. Now when we add or multiply even numbers, we get even numbers and we add 1, it's odd.
you multiply the one and the three and add the two
-1
31
The two numbers that satisfy the given conditions are 4 and 1. When you add 4 and 1, you get 5. When you multiply 4 and 1, you get 4. The two numbers are 4 and 1.
7
-1
-1
There are no two real numbers that do, but the complex numbers (2 + i) and (2 - i) will.If you want two numbers that multiply to negative 5 and add to positive 4 then: -1 and 5If you want two numbers that multiply to negative 5 and add to negative 4 then: 1 and -5
-17
-1