Answer: x = -2
<u>Step-by-step explanation:</u>
vertical line means it will be x = ___
Set the x-values equal to each other and solve for x.
3 - 2x = x + 9
<u> +2x</u> <u>+2x </u>
3 = 3x + 9
<u>-9 </u> <u> -9 </u>
-6 =3x
-2 = x
We can use ratios and the cross-multiply-divide to find this.
The ratio 21:5 is avaliable via the question. We then need to compare that to the ratio x:100, the 100 being the percent and the x being the number of airplane parts.
21/5 = x/100
We can then solve for x to find the number of airplane parts. First we multiply by 100 on both sides to get 2100/5 = x. Therefore x = 420 and there are 420 airplane parts.
You were right, its the second choice CA=CB+BA
