80.
Write a simplified expression for the area of the given figure.
4y2=height
7y3=base
½ base * height = area
½ * 7y^3 *4y^2
5.3
66. (5x + 4)(x2 - 3x + 2)
5x^3-15x^2+10x 4x^2-12x+8 5x^3-11x^2-2x+8
82. Rectangular Garden A rectangular garden has a perimeter of 500 feet.
(a) If one side of the garden has length x, then write a polynomial expression that gives its area. Multiply this expression completely.
(b) Evaluate the expression for x = 50 and interpret your answer.
5.4
74.
Find a polynomial that represents the following.
(a) The outside surface area given by the six sides of the cube
(b) The volume of the cube
(2x + 1)( 2x + 1)( 2x + 1) L * W * H
a) 6 * 2x+1* 2x+1
b) (2x+1)(2x+1)(2x+1)=
(2x+1)(2x+1)
8x^3+8x^2+2x+4x^2+4x+1
Combine like terms
8x^3+12x^2+6x+1
5.5
46. (a)
(x4y2)2
(-2 x2y-2)3
94. Distance to the Moon The moon is about 240,000 miles from Earth.
(a) Write this number in scientific notation.
(b) If a rocket traveled at 4 * 10^4 miles per hour, how long would it take for it to reach the moon?
2.4 X 10^5 miles
b. v = x/t Formula for velocity
vt = x Multiply both sides by t
t = x/v Divide both sides by v
t = (2.4 X 10^5) Substitute in the values of the variables (4 X 10^4) t = 2.4/4 * 10^5/10^4 Group the constants and the powers of ten
t = .6 * 10 Simplify the fractions
t = 6 hours Multiply the remaining power of 10
5.6
54. A student simplifies the expression 4 x3 - 1
4 x2 to x - 1.
Explain the student’s error.
The answer should be 1
6.2
Factor the trinomial completely.
66. -y3 + 9y2 - 14y
The GCF for this problem is -1y -y(y^2-9y+14)