Drag the tiles to the correct boxes to complete the pairs.
Model each problem as an equation, and then match it to its solution.
Tiles
The sum of the squares
of two positive integers is
185. If one integer is 3
less than the other, find
the larger integer.
The numerator of a
fraction is 1 more than
twice its denominator. If 4
is added to both the
numerator and the
denominator, the fraction
reduces to . Find the
denominator.
The difference of a
positive integer and its
inverse is . Find the
integer.

Respuesta :

For the first problem, the integers are 8 and 11.
The second problem has missing information.  So does the third.  They cannot be worked without the information that's missing.

Explanation:
Let x be the larger integer and y be the smaller integer.  We know that the smaller integer, y, is 3 less than the larger integer, x, so:
y=x-3

The sum of their squares is 185.  This means:
x²+y²=185
x²+(x-3)²=185
x²+(x-3)(x-3)=185

Multiplying the binomials we get:
x²+x*x-3*x-3*x-3(-3)=185
x²+x²-3x-3x+9=185

Combining like terms we get:
2x²-6x+9=185

When solving quadratics, we want the function to equal 0; subtract 185 from both sides:
2x²-6x+9-185=185-185
2x²-6x-176=0

Use the quadratic formula:
[tex]x=\frac{-b\pm \sqrt{b^2-4ac}}{2a} \\ \\=\frac{--6\pm \sqrt{(-6)^2-4(2)(-176)}}{2(2)}=\frac{6\pm \sqrt{36--1408}}{4} \\ \\=\frac{6\pm \sqrt{1444}}{4}=\frac{6\pm 38}{4}=\frac{6-38}{4}\text{ or }\frac{6+38}{4}=\frac{-32}{4}\text{ or }\frac{44}{4}=-8\text{ or }11[/tex]

Since both integers must be positive, x = 11.  This means that y=11-3=8.