Question

Solve the system by substitution.
2x+y=-11
3x-4y=11

A.(3, 5)
B.(–5, –3)
C.(–3, –5)
D.(5, 3)

Answer 1

first pick what you want so solve for. (get a variable alone on one side)

Answer 2

2x+y=-11
3x-4y=11
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solve
2x+y=-11 for y

Answer 3

2x+y=-11 (1) 6+5=11 you have -11 (1) -10-3=-13 not -11
=>A. =>B
3x-4y=11
(1)=>-6-5=-11
A.(3, 5) =>C, (2)=>-9=20=11
B.(–5, –3)
C.(–3, –5) (1)=> 10+3=13 you have -11
D.(5, 3) =>D

so only C is right?