Question

Solve the system by elimination

-3x + y = -20
3x - 2y = 19


A: (7,1)
B: (-1,-7)
C: (-7,-1)
D: (1,7)

Answer 1

Answer: A
Explanation: add the two equations to cancel out the x terms and end up with y=1. Now that we know what Y is, substitute 1 for y in any one of the equations and solve for x. X=7, Y=1

Answer 2

Given:-

-3x + y = -20 ----- eqⁿ( 1 )

3x - 2y = 19 ----- eqⁿ( 2 )

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Add the eqⁿ ( 1 ) to eqⁿ ( 2 ) ~

-3x + y = -20

3x - 2y = 19

____________

-1y = -1

y = -1/-1

y = 1

—————————————————————

now put the value of y = 1 in eqⁿ ( 2 )

3x - 2y = 19

3x - 2( 1 ) = 19

3x - 2 = 19

3x = 19 + 2

3x = 21

x = 21/3

x = 7

—————————————————————

x = 7 nd y = 1.

Ans :- Option A ) 7 , 1

hope it helps!:)