Radical Equations Problem

8(x+4) + x² = 96

8x+32x² = 96

x² + 8x - 64= 0

x² + 8x +16 = 80

(x+4)² = 80

x = -4-4√5

or x = -4+4√5

2. A positive real number is 4 less than another. If the sum of the squares of the two numbers is 72, then find the numbers.

Solution

Let one number be x

The other number is x+4

(x+4)² + x² = 72

x²+x² + 8x + 16 = 72

x² + 4x – 28 = 0

x² + 4x = 28

(x+2)² = 32

x = -2±√32

x= -2+√32

or x = -2+√32

3. The area of a rectangle is 46 square inches. If the length is 4 times the width, then find the dimensions of the rectangle. Round off your answers to the nearest hundredth.

Solution

x(4x) = 46

 x² - 46 = 0

4x² = 46

x² = 23

x² = 11.5

x = -3.39

or

x = 3.39

ignore -3.39

Hence, the dimensions are;

Length = 3.39x4 =13.56 Inches

Width = 3.39 Inches.

4. If the sides of a square measure units, then find the length of the diagonal.

Solution

Let the length of the diagonal be x

X² = (9√3)² + (9√3)²

X² = (81x3) + (81x3)

X² = 486

X = 22.05 Units

5. The area of a rectangle is 20 square inches. If the length is 4 inches less than 6 times the width, then find the dimensions of the rectangle. Round off your answers to the nearest hundredth.

Solution

Let the width be x

Length = 6x-4

x(6x-4) = 20

x²-x-=0

(x-)=

Either x = -1.52(ignore)

Or x = 2.19

Length = 6(2.19)-4 = 9.14 Inches.

Width = 2.19 Inches.