It would help to first find the unit rate. We know that the plane flies 810 km per 1.5 hours. Divide by 1.5 on both sides:
810/1.5 = 540 km/hour
Then, multiply both the hour and the distance by 2:
540 * 2 = 1080 km/2 hours.
85700, 8570, 857, 85.7, 8.57, .857
What are you finding or solving?
15,17,19 are all odd numbers and add to 51
3/5+1/2=___
To add them together, convert both fractions so they have the same denominator.
3/5=6/10 and 1/2=5/10
6/10+5/10=11/10, or 1 1/10
1/2+3/8=___
Same for this one- convert both fractions so they have the same denominator.
1/2=4/8 and 3/8 stays the same
4/8+3/8=7/8
1/2+2/5
And again, convert both fractions so they have the same denominator.
1/2=5/10 and 2/5= 4/10
5/10+4/10=9/10
Hope this helps :-)