SOLUTION: Hello! Thank you for this great service. I have not studied algebra for more than 30 years. I am trying to brush up on my algebra skills in order to qualify for training. Here's m

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Question 296844: Hello!
Thank you for this great service. I have not studied algebra for more than 30 years. I am trying to brush up on my algebra skills in order to qualify for training. Here's my equation:
3a - 2{3a-2[1-4(a)-4(-1)]+5}
3a - 2{3a -2[1 -4a +4] +5}
3a - 2{3a -2 +8a -8]+5
3a -6a +4 -16a +16 +5
-19a +25 (the book says -19a + 10)I don't understand where did I go wrong?
Found 2 solutions by richwmiller, jrfrun:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
I don't see an equal sign. Do you see an equal sign? No equal sign-no equation.
3a - 2{3a-2[1-4(a)-4(-1)]+5}
3a - 2{3a -2[1 -4a +4] +5} ok up to here
3a - 2{3a -2 +8a -8]+5 this is wrong
3a -6a +4 -16a +16 +5
-19a +25 (the book says -19a + 10)
I don't understand where did I go wrong?
My solution
3a - 2{3a-2[1-4(a)-4(-1)]+5}
3a - 2{3a -2[1 -4a +4] +5}
3a-2{3a-2[5-4a]+5}
3a-2{3a-10+8a+5}
3a-2{11a-5}
3a-22a+10
-19a+10

Answer by jrfrun(3) About Me  (Show Source):
You can put this solution on YOUR website!
3a - 2{3a-2[1-4(a)-4(-1)]+5}
3a - 2{3a -2[1 -4a +4] +5}
3a - 2{3a -2 +8a -8]+5 you made a mistake in this step
it should have been
3a -2{3a-2+8a-8+5} where the last five is part of the -2 factor
followed by
3a -6a +4 -16a +16 -10
You would save yourself a ton of headaches by simplifing as you
3a - 2{3a-2[1-4(a)-4(-1)]+5}
3a -2{3a -2[1-4a+4]+5}
3a -2{3a-2[5-4a]+5}
3a-2{3a-10+8a+5}
3a-2{11a-5}
3a-22a+10=-19a+10