Answer:
x=15
Step-by-step explanation:
21:2x=7:10 can be rewritten as 21/2x=7/10
21/2x=7/10, cross multiply
= 14x=210
x=15
3.1 is like a example when it is hiding a zero behind it and you find this when you do a math problem and you don't put zero in front of a number like 100-89 you don't write "011" so that is why it is like that
Answer:
the right answer would be 13
3ft per second on a still sidewalk (27/9) , 11ft on the moving sidewalk.(99/9)
Hope this helps!