Solve the system of equations.
\begin{aligned} & -5x+2y = 9 & y=7x \end{aligned}


−5x+2y=9
y=7x


x=x=x, equals
y=y=y, equals

Solution:

Given system of equations are:

-5x + 2y = 9 eqn 1

y = 7x eqn 2

We have to solve the system of equations

Substitute eqn 2 in eqn 1

-5x + 2(7x) = 9

-5x + 14x = 9

Combine the like terms : -5x + 14x = 9x

Therefore,

9x = 9

Divide both sides by 9

Substitute x = 1 in eqn 2

y = 7(1)

Thus solution is (x, y) = (1, 7)

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.