4

Wed 3 Dec, 2014 07:01 pm
5/8(a-2) = 10
5(a-16) =80
5a - 80 =400
5a = 400
a = 96

Question
a)
substitute the solution a=96 in to the left -hand side of the equation 5/8(a-2)=10 and explain why this show that is incorrect
b)
what is full and correct equation and check the solution
c)
identify two lines where a mistake has been made,explain why is incorrect
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Type: Question • Score: 4 • Views: 1,413 • Replies: 6
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jespah

1
Wed 3 Dec, 2014 07:20 pm
@sarahjunnek,
0 Replies

BioB

1
Wed 3 Dec, 2014 07:38 pm
@sarahjunnek,
From this syntax, this should be the correct course of solving the equation:

5/8(a-2)=10 //multiply both sides by 8(a-2)
5=10*8(a-2)
5=80(a-2)
5=80a-160 //add 160 to both sides
5+160=80a
165=80a //divide both sides by 80
165/80=a
a= 33/16

Kolyo

1
Wed 3 Dec, 2014 08:02 pm
@BioB,
Great! Another contributor to the Math threads.

Welcome to a2k. 0 Replies

Wilso

1
Wed 3 Dec, 2014 08:09 pm
The exact structure of the question is not clear from the original post.
fresco

1
Thu 4 Dec, 2014 01:18 am
@Wilso,
Correct. A fractional answer is unlikely.

Perhaps (5/8)(a-2)=10 would be better.
whence 5a - 10 =80
5a=90
a=18

A much more likely solution in elementary algebra (age 11 in the UK).

Wilso

1
Thu 4 Dec, 2014 03:07 am
@fresco,
That's how I saw it.
0 Replies

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