15/10 = 18-x/x is the ratio of the larger to the smaller triangle
Cross multiply:
15x = 10(18 - x)
15x = 180 - 10x
25x = 180
x = 7.2
Plug back in to check
15/10 = 1.5
18-7.2/7.2 = 10.8/7.2 = 1.5 :)
Answer:
The side lengths of similar triangles are proportional
Step-by-step explanation:
Let’s call the speed of the slower car S, then the speed of the other is S+10mph.
At 5pm they have been travelling for 3 hours. The slower car travels a distance 3S and the faster one 3(S+10).
But the two distances must add up to 240 miles so 3S+3(S+10)=240, 3S+3S+30=240, 6S=210, S=35 mph. The faster car’s speed is 45mph. We can see that 3S is the same distance as 3x, so x=S=35 mph, and the distance the faster car travels is 3×45=135 miles.
