Question

Problem 1
Evaluate the expression 1/2x + 14 if x = 23.
I got 25.5

Problem 2
14x = 2 (5x + 14)
I got 3.5

Problem 3
(x + 20) + (2x + 10) = 90
I got 20.

Please tell/show me your steps. I want to make sure that I did it right.

Answer 1

Is the first one supposed to say "if x = 23" instead of "if x - 23" ?

Answer 2

Yes, sorry about that.

Answer 3

also, is problem 1: (1/2x) + 14 or (1/2)x + 14

Answer 4

They didn't put any parenthesis. I assume it would be (1/2x).

Answer 5

Does it look like:\[\frac{ 1 }{ 2 }x \]

or \[\frac{ 1 }{ 2x }\]

Answer 6

The first one.

Answer 7

so, (1/2)x when x = 23 is (23/2) = 11.5

and (1/2)x+14 = (1/2)(23) + 14 = 25.5

Answer 8

Problem 1
Evaluate the expression 1/2x + 14 if x = 23.
\[\frac{ 1 }{ 2 }(23)+14\]
11.5+14 = 25.5

Answer 9

if you understand that one, you should be able to give the other problems a try. If not, speak up :)

Answer 10

@Jake: I already worked on the problems I stated in the original question. I'm just confirming that I did it correctly. :)

Answer 11

Thank you both for question 1. :)

Answer 12

Problem 2
14x = 2 (5x + 14)

Distribute the 2 first
14x = 10x + 28
then isolate the variables to only one side of the equation by subtacting 10x from both sides
14x = 10x + 28
-10x = -10x
----- ------
4x = 0 + 28
OR
4x=28
Then, divide both sides by the number which is glued to the variable...in this case 4
4x = 28
--- ----
4 4
---------------
1x = 7
OR
x= 7

Solve for x? Answer is 7

Answer 13

Oh okay. I forgot to distribute the 2 in problem 2. Thank you very much!

I am positive about problem 3.

Answer 14

Since the commutitative property states that addition can be in any which order than the parenthesis can be removed.

(x + 20) + (2x + 10) = 90
is now
x + 20 + 2x + 10 = 90
reorganize and combine like terms
(1)x + 2x + 20 + 10 = 90
= = =
3x +30 = 90
New problem looks like
3x +30 = 90
isolate the number that is glued to the variable on one side of the equation by subtracting 30 from both sides
3x +30 = 90
-30 -30
---- ----
3x +0 = 60
OR
3x = 60
Then, divide both sides by the number which is glued to the variable...in this case 3

3x = 60
-- ---
3 3
------------
1x = 20
OR
x = 20

solve for x? answer is 20

Answer 15

Okay, thanks! :) I got the same answer as well.