Step-by-step explanation:
all work is shown and pictured
Answer:
Step-by-step explanation:
The matrix system for the linear equations: x + 2y = 8, 2x + 6y = 9
To get the coefficient of x and y, the inverse of the first matrix (let the first matrix be A) must be known.
= (1 / determinant of A) x Adjoint of A
the determinant of A = (1 x 6) - (2 x 2) = 6 - 4 = 2
Adjoint of A =
= =
Answer:
b
Step-by-step explanation:
i took the test
Given:
A train travels 288 km at a uniform speed.
If the speed has been 4 km per hour more it would have taken one hour less for the same journey.
To find:
The initial speed of the train.
Solution:
Let x km/h be the initial speed on the train.
New speed of train = (x+4) km/h
We know that,
Time taken by the train initially to cover 288 km is hours.
New time taken by the train to cover 288 km is hours.
It is given that If the speed has been 4 km per hour more it would have taken one hour less for the same journey.
Splitting the middle term, we get
We know that the speed cannot be negative. So, the only possible value of x is 32.
Therefore, the speed of the train is 32 km/h.