Red lined an example of your problem would help
Solve for x:
10 (x + 2) = 5 (x + 8)
Expand out terms of the left hand side:
10 x + 20 = 5 (x + 8)
Expand out terms of the right hand side:
10 x + 20 = 5 x + 40
Subtract 5 x from both sides:
(10 x - 5 x) + 20 = (5 x - 5 x) + 40
10 x - 5 x = 5 x:
5 x + 20 = (5 x - 5 x) + 40
5 x - 5 x = 0:
5 x + 20 = 40
Subtract 20 from both sides:
5 x + (20 - 20) = 40 - 20
20 - 20 = 0:
5 x = 40 - 20
40 - 20 = 20:
5 x = 20
Divide both sides of 5 x = 20 by 5:
(5 x)/5 = 20/5
5/5 = 1:
x = 20/5
The gcd of 20 and 5 is 5, so 20/5 = (5×4)/(5×1) = 5/5×4 = 4:
Answer: x = 4
This is how you set up a percent of error proportion:
<u>Amount of error</u> <u>x(Unknown percent)</u>
Actual value = 100(Percents are out of hundreds)
So if you fill it in, it becomes <u>4</u> <u>x
</u> 80 =100
Cross multiply, 400= 80x.
Solve.
x=5 so percent error is 5%<u>
</u>
