Questions on Algebra: Expressions involving variables, substitution answered by real tutors!

Tutors Answer Your Questions about Expressions-with-variables (FREE)

Question 15236: Does the sentence "Solve 2x - 3(4x + 1)" make sense? Why or why not?
Click here to see answer by Tonilady(4)

Question 15237: Solve: 1 + 4(2c- 3) = 3(3c-5)
Click here to see answer by rahman(247)

Question 15356: Solve: 4 - 3(2p + 1) = 3p + 11
Click here to see answer by rahman(247)

Question 15346: I need this problem broken completely down please. The problem is giving the solution, but it seems to me as if there is a trick to it.
If 3 + 2(4a - 3)= 5 and 4 - 3(2 - 3b) = 11, which is larger, a or b?
Click here to see answer by rahman(247)

Question 15550: 3-4z=-5+8z
Click here to see answer by Dont_Understand(8)

Question 15550: 3-4z=-5+8z
Click here to see answer by elima(1433)

Question 15577: hello,
i know i have done this sort of problem in the past but can't get answer that matches the book the answer 7 the problem is 8x - 13 = 43
Click here to see answer by pwac(253)

Question 15653: Solve: 3t - 4(5 - t) = t - 8
Click here to see answer by rahman(247)

Question 15668: I have more than one question: 2m+5=m over 5-4, m over 2+3 = m over 5+5,3x+4(x-2=7+x,6(2x+7)=102,x+7=2(x-1), 6(x+2x+1)=12x.
Click here to see answer by pwac(253)

Question 15859: 2y+18=12-6(y+7)
Click here to see answer by bfis20(3)

Question 15888: I have no idea how to solve this problem!
The pressure at a certain depth in the ocean can be approximated by the equation P = 15 + 1/2 D, where P is the pressure in pounds per square inch and D is the depth in feet. Use this equation to find the depth when the pressure is 40 lb/in^.
Click here to see answer by venugopalramana(3286)

Question 15825: 17=2(2x+9)

Click here to see answer by pwac(253)

Question 15902: Find two numbers whose sum is 58 and whose difference is 16.
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Question 15920: If x-1/3y=3, then the value of 3x-y-6=?
Click here to see answer by Maricel Balos(8)

Question 15951: the problem ,solve the equation or formula for the variable specified.I can do this when numbers are involved but am having problems with this one.
d=rt solve for variable r
Click here to see answer by pwac(253)

Question 15994: I'm getting confused in the first step of equations with variables on both sides. For example: 7c- 4=9c- 11 I know that you put the variables together but I don't know when to add , subtract, multiply or divide. Then if I do get help on it and get to the next step I'm getting confuse so please help me understand how to do these. Thanks,Kristen
Click here to see answer by elima(1433)

Question 16022: my question is on solving equations with variables on both sides
Click here to see answer by rapaljer(4667)

Question 16103: ineed help! i really need step-by-step instructions on how to solve equations, i almost cant do them at all and i have a test coming up. i most need help in long ones and ones with fractions such as 10(y+2)divided by seven =2y-4
Click here to see answer by askmemath(368)

Question 16113: 5(x-6)+6=7(x+2)-8
My problem with this one is just when i think i have it figured out i realize i took the wrong term and moved it to the wrong side! How do i know what term to move to what side???
On this problem i took away the parenthasis then i combined like terms next i would do what??
Add 24 to both sides?? or subtract 7x on both sides (how do i know???)
Click here to see answer by askmemath(368)

Question 16212: e-3=-2
Click here to see answer by elima(1433)

Question 16286: Anna is twice as old as her brother Dennis, who is 4 years older than their brother Curtis. The sum of their ages is 32. How old is Anna?
We need the equation not the number answer.
Thank you.
Click here to see answer by pwac(253)

Question 16251: (5-y)+(6-y)-(5-y)=0 what does y equal???
Click here to see answer by MathGrace(6)

Question 16251: (5-y)+(6-y)-(5-y)=0 what does y equal???
Click here to see answer by hyh_124(6)

Question 16449: Im not sure im posting this in the right place, but i need help solving this problem: 4xy(3x+8x-3)
Click here to see answer by rahman(247)

Question 16403: What is 15 decreased by z? How can I write a mathimatical expression for this problem?
Click here to see answer by elizabeth2005(20)

Question 16568: solve using substitution
2x + y = 4
3x + 2y = 1
Click here to see answer by kikerkins(17)

Question 16320: what about combining like terms

Click here to see answer by rapaljer(4667)

Question 16688: -2(2x+x)
Click here to see answer by Kimi R Rtichie(3)

Question 16708: 1.) 3x+y=15
y=3
2.)3x-2y=12
-y+9=x
Click here to see answer by elima(1433)

Question 16718: "the product of 10 and a number p"
Click here to see answer by lainey(7)

Question 16722: Please help me solve this equation. 8p - 5(p + 3) = (7p - 1)3
Click here to see answer by glabow(165)

Question 16733: I tried to solve this equation but I believe it is wrong:

5r-2(2r+8)=16
-2(2r)+-2(8)=16
5r-4r+-16=16
-r-16=16
-r-16+16=16+16
-r=32
-----
1 1
r=-32
1=
Click here to see answer by rahman(247)

Question 16754: Algebra.com has been a God send. I have lost many, many hours of family time because of this Algebraic story problem. Any assistance would be greatly apprecited.
A cookie company makes three kinds of cookies, oatmeal raisin, chocolate chip, and shortbread, packaged in small, medium, and large boxes. The small box contains 1 dozen oatmeal raisin and 1 dozen chocolate chip; the medium box has 2 dozen oatmeal, 1 dozen chocolate chip, and 1 dozen shortbread; the large box contains 2 dozen oatmeal raisin, 2 dozen chocolate chip, and 3 dozen shortbread. I you require 15 dozen oatmeal raisin, 10 dozen chocolate chip, and 11 dozen shortbread cookies, how many of each size box should you buy?
Thank you very much.
Click here to see answer by rapaljer(4667)

Question 16779: 4/x+3 - x/x-3 - 18/x^2-9
Click here to see answer by xcentaur(357)

Question 16591: The diffrence of two numbers is 12.Two fiths of the greater number is six more than one third of the lesser number.Find both numbers.
I've 2/5(x+12)=6+1/3x but i cant get answer
Click here to see answer by xcentaur(357)

Question 16862: 2m+12=3m-31
Click here to see answer by piglet162431(90)

Question 16937: Please Help: 9(11-k)=3(3k-9) The answer is 10 i think and im not sure how to get there. Thank you!
Click here to see answer by venugopalramana(3286)

Question 16899: [-3+(-6)]SQAURED - [-8-2(-3)]SQAURED
I MULTIPLIED NEG 3 TO NEG 6 GOT 18. THEN SQAURED, GOT 81.
SECOND PART IS WHERE I GET STUCK-
NEG 8 NEG 2 = POS 10.THEN I TRIED MULTIPLYING TO 3SQUARED, IT WAS WRONG,( ACCORDING TO THE BACK OF THE BOOK) SO THEN I TRIED, 10 MINUS 9 GOT 1-WRONG.
THEN I MULTIPLIED 13 TO 13, GOT 169 MINUS 81-GOT 88. WRONG AGAIN.
I HAVE JUST ABOUT PUT A WHOLE THROUGH MY PAPER. PLEASE HELP. I HAVE A MAJOR TEST TOMORROW. ALSO, I WOULD LIKE TO KNOW WHY b-c, IF b=-7 AND c=12 ISN'T 5 BUT NEG 12?!?! THANK YOU
Click here to see answer by pwac(253)

Question 17085: 3(4x+6)+7x
Click here to see answer by tjnw79(57)

Question 17088: 3x+7=x
Click here to see answer by tjnw79(57)

Question 17097: The Eiffel Tower is 497 ft. taller than the Washington monument. If you take 58 ft. off both heights, the Eiffel Tower is twice as highas the Washington monument. How tall is each tower?
Click here to see answer by rapaljer(4667)

Question 17066: Really, expressions involving variables, subtraction: I am trying to solve by subtraction instead of graphing. I have tried 6x+21minus-4x+31 and came up with 2x + -10 which doesn't work for the problem. How would I find he constant for the variables? What steps do I take to solve it correctly? Thank you for the help!
Click here to see answer by rapaljer(4667)

Question 17157: y+3x= -5
2y-3x= 9
I'm supposed to use elimination to find the solution, but I keep coming up with an impossible answer.
Click here to see answer by venugopalramana(3286)

Question 17442: s=2wl+2lh+2wh solve for l
Click here to see answer by bam878s(77)

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