Question

1.solve the system by substitution

-2.5x+y=13.5
2.25x-y=12.25

A: (-5,1)
B: (-1,5)
C: (1,-5)
D: (5,-1)

2.solve the system using elimination.

2x+6y=-12
5x-5y=10

A: (2,1)
B: (0,-2)
C: (-2,0)
D: (1,2)

3.what is the solution to the following system.

-3x-2y=-12
9x+6y=-9

A: (2,1)
B: no solution
C: (-2,-1)
D: infinitely many solutions

4. what is the solution to the following system.

3x+2y=7
-2x+3/4y=-13

A: (5,4)
B: (-5,4)
C: no solution
D: infinitely many solutions

Answer 1

Are you still typing

Answer 2

there are 4 ways to solve simultaneous equations and it is a very good practice to always check your solution in the original.
to use substitution write the equation for 1 variable in the first equation and use this expression in the second equation. you will now have one equation with one variable solve for the unknown value. use this value in the expression to calculate the value.

the elimination method; the objective is to make the coefficient of one variable equal and opposite so that when you add the equivalent equations the chosen variable will be eliminated. proceed to solve the equation with one unknown and use this value in either original to calculate the value of the eliminated variable.

the 3rd method is by graphing each line and finding the intersection

the fourth is by using matrix

Answer 3

so that was a yes