2x-5y=16 =>10x-25y=80
5x+3y=9 => 10x+6y=18
subtract one from the other: (6-(-25)y=(18-80), 31y=-62, y=-2
plug y=-2 in 2x-5y=16 to find x: 2x+10=16, x=3
12x+y=12*3-2=34
When using scientific notation, you only want one number to be in front of the decimal place. If you have to make the number smaller, then the 10^nth power will be positive. If you have to make the number bigger, then 10^nth power will be negative. Example:
0.54 --> 5.4 * 10^-1
35 --> 3.5 * 10^1
The value of n depends on how many spaces the decimal point needs to be moved. For your question, putting 23 in scientific notation would look like this:
23 --> 2.3 * 10^1
Answer:

Step-by-step explanation:
we have

Applying property of exponents

