Linear Combinations??

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Linear Combinations??

Using addition, use linear combinations to solve the linear system.

x+y= 4
x-y= -10

2006-10-10 14:27:10 · 3 answers · asked by singing soul 2 in Education & Reference ➔ Homework Help

3 answers

Solve,

x + y = 4 ... (1)

x - y = - 10 ... (2)

Take (1) + (2),

x + x + y - y = 4 - 10

2x = -6

x = -6/2

x = -3 ... (3)

Substitute (3) into (1)

(-3) + y = 4

y = 4 + 3

y = 7

2006-10-10 14:32:20 · answer #1 · answered by ideaquest 7 · 0⤊ 0⤋

Add each part of the equations together. The y's cancel, so you have 2x = -6. Divide, and you get x = -3. Substitute into either equation, and you'll find y = 7.

2006-10-10 14:30:14 · answer #2 · answered by dmb 5 · 0⤊ 0⤋

adding 2 equation => 2x = -6
=> x = -3
replqce x =-3 into any of two equation => y= 7

2006-10-10 14:42:00 · answer #3 · answered by hoang_hiepsi 4 · 0⤊ 0⤋