I Think the answer is 31 because 20-5 is 15 so 36-5 is 31
5x+(-4)-5x=6x+4-5x
-4=x+4
x=-8
To get rid of 5x on the left side.
Answer: it will take him 4.5 hours to cover same distance
Step-by-step explanation:
Marathon runner covered the whole distance in 4 hours running at a constant speed of 8.1 km per hour.
Speed = distance / time
Distance = speed×time
Therefore, distance covered by the marathon runner in in 4 hours, running at a speed of 8.1 km per hour is
8.1 × 4 = 32.4 kilometers
if he decreased the speed to 7.2 km per hour, the distance remains 32.4 kilometers. Therefore,
At 7.2 km per hour, the time it would take him to cover the same distance would be
Distance/ speed = 32.4/7.2 = 4.5 hours
Answer:
X = -2
y = 2
Step-by-step explanation:
Substitute y=x + 4 in the second equation to find x
x+4 = 2x + 6
subtract x from both sides
4 = x + 6
subtract 6 from both sides
-2 = x
put -2 in for x in the first equation
y= 2
5b-2=13 add 2 to both sides
5b=15 divide both sides by 5
b=3
