Help with algebra 1 please 10 points.?

Question

4.The ordered pair (1, -5) is a solution for the system x + 2y = -9 and x - y = 6.
True
False

5. Which of the following is a solution for the system y = -3x + 5 and y = 2x + 5?
(1, 7)
(5, 0)
(2, -1)
(0, 5)

Answer 1

x+2y=  -9 --------------->(1)

x-y=6------------------(2)

Substitute (1,-5) in the equation.(1)

1+2(-5)= - 9

1-10= - 9

-9=-9

Substitute (1,-5) in the equation.(2)

x-y=6

1- (-5) =6

1+5=6

6=6

Option A is right choice.

Answer 2

• 5).

Substitution method  :

The system of equations are y = - 3x + 5 and y = 2x + 5.

Substitute y = - 3x + 5 in y = 2x + 5.

- 3x + 5 = 2x + 5

- 3x - 2x = 5 - 5

- 5x = 0

⇒ x = 0.

Substitute the value x = 0 in y = - 3x + 5.

y = - 3(0) + 5

y = 0 + 5

⇒ y = 5.

The solution of the system is x = 0 and y = 5.

 

Fourth option is the correct choice.