Devon has been saving $5 & $10 for the past four years. Over spring break he wanted to see how much money he has saved up. After counting the money he calculated that he has a total of $395 & had 49 bills. Based on this information, how many $5 & $10 bills does he have?

19 five dollar bills

30 ten dollar bills

Step-by-step explanation:

x=number of $5 bills

y=number of $10 bills

x+y=49

x=49-y

5x+10y=395

substitute for x

5(49-y)+10y=395

245-5y+10y=395

245+5y-245=395-245

5y=150

5y/5=150/5

y=30

x=49-30=19

The answer is in the image 

F=ma

where F=force

m=mass

a=acceleration

Here,

F=4300

a=3.3m/s2

m=F/a

    =4300/3.3

    =1303.03kg

The answer is in the image 

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in $1800 sales

tip=18% of 75.45

     =18/100 * 75.45 = $13.581

Tip = $13.581

Area of rectangle= L*b

here,

L=12.4 cm

b= 8.8 cm

A= L*b

= 12.4 * 8.8 = 109.12 cm^2

Cost before sale tax=$46.00

Cost after including tax=$48.76

Sale tax=$48.76-46.00

=$2.76

we know,

sale tax=((sales tax rate)/100) * cost before sale tax

2.76=((sales tax rate)/100) *46.00

sale tax rate=(2.76*100)/46

                   =276/46

                    =6%

There fore sales tax rate=6%

The answer is in the image