Answer:
Step-by-step explanation:
Given is the system of equations:
a) Coefficient matrix is
7 3
-6 -3
b) |A|= -21+18=-3
c) Inverse =
1 --1
2 -7/3
c) Solution = product of inverse matrix * (12 4) Transpose
X1 = 16 and X2 =-100/3
Answer:
6.75 Is the right choice
Step-by-step explanation:
2 1/4 Divided by 1/3=6.75
Answer:
5 < x < 13
Step-by-step explanation:
9+4 > x
4 + x > 9
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