Step-by-step explanation:
2x - 3y = 9
2x + 3y = 3
__________ -
-6y = 6
y = -1
2x - 3y = 9
2x - 3(-1) = 9
2x - (-3) = 9
2x = 12
x = 6
Answer:

Step-by-step explanation:

1.742 x 10^-3
<em>This is because you have to move the decimal so there is no non zero digits left in the decimal point and if the number of decimal places you move will be the exponent on the "10". If you move the decimal to the right it will be a negative and if you move it to the left it will be a positive.
</em>
Well in my calculations I got: well if you he increases the speed by 2.6 per hour soo 4+2.6=6.6
Answer:
1. 8
2. 11
3. 14
4. 17
Step-by-step explanation:
When there is a number next to a number inside parenthesis, it means you multiply those together. Don't forget to use PEMDAS either. So you first multiply 3(and whatever number is inside) and then add 5. Hope this helped :)