Could someone me with the first two i don't understand and it's due tomorrow

If said number is x, that means that twice (2 times) a number and 2x-7=13. Adding 7 to both sides, we get 2x=20 and by dividing both sides by 2 we get x=10. For 2, we see that the sum of a number and 6 is first priority, so we have (x+6)*7=-43. Dividing both sides by 7, we get x+6=-43/7. After that, we subtract both sides by 6 to get -43/7-6=x

If the diameter is 8 than the radius is 4 because 2r or 2*radius equals the diameter. 4*2=8. 8/2=4.

now i kniw my abcs next time wont u sing with me