Question

PLEASE HELP QUICK!!

Answer 1

Answer:

28 miles in 1.4 hours in the city

Step-by-step explanation:

On the highway:

Time $=t$ hours

Rate = 45 mph

Distance $=45\cdot t$ miles

In the city:

Time $=3-t$ hours

Rate = 20 mph

Distance $=20\cdot (3-t)$ miles

The trip was 100 miles long, then

$45t+20(3-t)=100\\ \\45t+60-20t=100\\ \\45t-20t=100-60\\ \\25t=40\\ \\t=1.6\ hours\\ \\3-t=3-1.6=1.4\ hours$

Distance on the highway $=45\cdot 1.6=72$ miles

Distance in the city $=20\cdot 1.4=28$ miles