Answer:
Step-by-step explanation:
Time for first race 57.9seconds
x=time for first half of race
x-4.7=second half of race
Equations is
x + (x-4.7)=57.9
2x-4.7=57.9
2x=57.9+4.7
2x=62.6
x=31.3
Check answer
31.3 + (31.3-4.7)=57.9
31.3 +26.6=57.9
57.9=57.9