Gabe went ot lunch with his best friend the bill costs 16.40 dollers before trax and tip he paid a 9 persent tax and left a 20 persent tip howm much did gabe spend

Step-by-step explanation:

Gabe went out for lunch with his best friend the bill costs $16.40

This amount was before tax and the tip that he wanted to give.

He paid a 9 percent tax on the bill. The amount of the 9 percent tax is 9/100 × 16.40 = 0.09 × 16.40 = $1.476

He left a 20 percent tip. This means that amount left as tip is 20/100 × 16.40 = 0.2×16.40 = $3.28

The amount that Gabe paid would be the sum of the bill, the tip and the amount paid on tax. It becomes

16.40 + 1.476 + 3.28 = $21.156

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional