The number of Euros received against 600 dollars = 450
Then
For 1 dollar, the number of euros = (450/600) euros
= (45/60) euros
= ( 3/4) euros
= 0.75 euros
So the unit rate that describes the exchange rate is 0.75 euros per dollar. So the correct option among all the options given in the question is option "A".
I hope the procedure for
getting to the correct result is clear enough for you to understand. In future
you can use this procedure for solving similar problems.
X*a = 244 is equation (1)
x+a = 2 is equation (2)
Solve equation (2) for 'a' to get
x+a = 2
a = 2-x
Call this equation (3)
We will plug equation (3) into equation (1)
x*a = 244
x*(a) = 244
x*(2-x) = 244
Notice how the 'a' is replaced with an expression in terms of x
Let's solve for x
x*(2-x) = 244
2x-x^2 = 244
x^2-2x+244 = 0
If we use the discriminant formula, d = b^2 - 4ac, then we find that...
d = b^2 - 4ac
d = (-2)^2 - 4*1*244
d = -972
indicating that there are no real number solutions to the equation x^2-2x+244 = 0
So this means that 'x' and 'a' in those two original equations are non real numbers. If you haven't learned about complex numbers yet, then the answer is simply "no solution". At this point you would stop here.
If you have learned about complex numbers, then the solution set is approximately
{x = 1 + 15.588i, a = 1 - 15.588i}
which can be found through the quadratic formula
Note: it's possible that there's a typo somewhere in the problem that your teacher gave you.
The answer is 3/4 and it was already simplified
10
Therefore, the greatest common factor of 30 and 50 is 10.