6th grade excellerated math word problem

Question

A mini van and suv are traveling at the same speed. The minivan drives 4 hours. The suv drives another half hour and goes 35 miles more. Let x be the speed of the cars. Which equation can be solved to find out how fast the cars are going? 

 

4x + 35 = 3.5x 

4x + 35 = 2.5x

4x= 2.5x + 35

4x = 3.5x + 35

Answer 1

d = r · t

35 = x · 0.5        SUV goes 35 miles in one-half hour

 

The equations/solutions are rather convoluted - from my perspective as a teacher.

The fourth one can be rearranged:

 

4x = 3.5x + 35

0.5x = 35               subtract 3.5x form both sides.

 

Yet I do not understand how anyone would get that directly from the problem.

The second sentence - that one I used - is very clear on the distance and time.