Question

1. Justin’s car can travel 77.5 miles using 3.1 gallons of gas.

Answer 1

Distance/fuel=ratio 77.5/3.1 is proportional to xdistance/8.2 77.5/3.1=x/8.2 multiply both sides by (3.1*8.2) 635.5=3.1x divide both sides by 3.1 205=x 205 miles 2. easy peasy one way is boys+15=girls boys+girls=85 boys+boys+15=85 minus 15 2boys=70 divide 2 boys=35

Answer 2

1)  Write this as a ratio...

77.5 miles / 3.1 gallons = x miles / 8.2 gallons

Solve for x... multiply by 8.2 gallons on both sides (that cancels it on the right) side of the equation.

8.2 gallons * 77.5 miles / 3.1 gallons = x
635.5/ 3.1 = x
211.83 miles = x

Justin travels 211.83 miles on 8.2 gallons of gas

2) If we let boys = b, then girls has to be b + 15 (since there are 15 more girls than boys).  Now together there are 85 members of the band so... boys + girls = 85  and since girls is b + 15, then...

b + b+15 = 85

Now solve for b.  First combine like terms...

2b + 15 = 85

Now subtract 15 from each side (cancels the 15 on the left)

2b + 15 - 15 = 85 - 15
2b = 70

Now divide each side by 2 (cancels 2 on the left)

2b / 2 = 70 / 2
b = 35

So there are 35 boys in the band.

Just FYI, that also means there are 35+15 = 50 girls.  Just so happens that 50 + 35 = 85 so our work checks!