Can u answer all three and in 20-30 minutes or quicker if u can i just not understanding the math they are giving me

18).  16:80 is the ratio but in simplest form is; 5:0

19).   36:54 is the ratio but in simplest form is; 2:3

20).   12:24 is the ratio but in simplest form is; 1:2

hope that helps:D

rounding to the nearest thousandth would be 452,000

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116