For questions 9 through 12, plug in the term you're looking for in for x: 9. y=10(20)-2=298 10. y=10(9)-2=88 11. y=5(2^5)=160 12.y=5(2^7)=640
For questions 13 through 16, plug the values 1 through 5 in for x, one at a time: 13. y=4^1=4, y=4^2=16, y=4^3=64, y=4^4=256, y=4^5=1,024 14. y=(-3)^1=-3, y=(-3)^2=9, y=(-3)^3=-27, y=(-3)^4=81, y=(-3)^5=-243 15. y=-3^1=-3, y=-3^2=-9, y=-3^3=-27, y=-3^4=-81, y=-3^5=-243 16. y=10^1=10, y=10^2=100, y=10^3=1,000, y=10^4=10,000, y=10^5=100,000
For question 17, plug 4 in for n: 17. f(4)=5^4=625
In a regular decagon like the one shown in the picture each angle is 144 degrees and it all adds up to 1,440. If you want proof search up "angle of a decagon"
This is a simple Pythagorean Theorem problem. 7 is the hypotenuse so you would do c^2-a^2=b^2. In this case 7^2-2^2=b^2. 7^2 is 49 and 2^2 is 4 so you have 49-4=b^2. 49-4 is 45. The square root of 45 is 6.70. So x=6.70