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I need help with these answers.?

+1 vote
I used to understand but I tried looking up tutorials. Help anyone?

1. Simplify the expression 54. (1 point)
a. 20
b. 1,024
c. 125
d. 625

2. Simplify the expression (20 – 14)2 ÷ 12. (1 point)
a. 1
b. 3
c. 17
d. 0.5
3. Evaluate the following expression: (7 + 5b) + 1 , if b = 3. (1 point)
a. 27
b. 23
c. 0
d. 24
4. Suppose you make $12 an hour as a lifeguard at the community pool during the summer. Let h represent the number of hours you work in a week. Write an expression that represents the amount of money you earn in a week and evaluate it for h = 15. (1 point)
a. 12h; $180
b. 12 + h; $27
c. 7(12h); $1,260
d. 5(12h); $900

If you could explain that would be nice.
asked Jan 16, 2013 in PRE-ALGEBRA by anonymous Apprentice

3 Answers

+1 vote

2.

Order of Operations:

To simplify the expression follow the order of operations: (PEMDAS)

1.      Evaluate the expressions inside the Parenthesis/Brackets (P).

2.      Evaluate Powers/Exponents (E).

3.      Multiply and/or Divide in order from left to right (MD).

4.      Add and/or Subtract in order from left to right (AS)

A simple technique for remembering the order of operations is turned into phrase "Please Excuse My Dear Aunty Sally".

simplify the expression (20 – 14)2 ÷ 12 using order of operations.

First operation is evaluating expression within the parenthesis.

= (6) 2 ÷ 12

= 12 ÷ 12

Next opeartion is division

= 1

Option a is right choice

answered Jan 16, 2013 by steve Scholar
+1 vote

3. Substiute b = 3 in expression (7 + 5b) + 1.

= (7 + 5 * 3) + 1.

Simplify the expression by applying order of operations (PEDMAS)

First operation is evaluating the expression within the parenthesis

= (7 + 15) + 1.

=( 22) + 1

Next operation is addition.

=23

Option b is right choice.

answered Jan 16, 2013 by steve Scholar
+1 vote
Amonut per hour = 12$

Number of hours per week = h

Write an expression for the current situation:

Amount of money you earn per week = Number of hours per week X Per hour rate

                                                                  = h X 12

Substitute h = 15 in the expression

Amount of money you earn per week = 15 X 12 = 180$

 

Option a is right choice

 

I hope it helps a lil.
answered Jan 16, 2013 by steve Scholar

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