SOLUTION: Solve the linear system -13=4x-3y 5x+2y=1

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Question 1132157: Solve the linear system -13=4x-3y 5x+2y=1
Found 2 solutions by MathLover1, greenestamps:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

-13=4x-3y+.........eq.1
5x%2B2y=1++.........eq.2........solve for x
-----------------------------------

5x%2B2y=1++.........eq.2
x=-2y%2F5%2B1%2F5++.............substitute in eq.1

-13=4%28-2y%2F5%2B1%2F5+%29-3y
-13=-8y%2F5%2B4%2F5+-3y ...both sides multiply by 5
-65=-8y%2B4-15y+
-65=-23y%2B4
23y=4%2B65+
23y=69+
y=3+
go to x=-2y%2F5%2B1%2F5++........., substitute y
x=-%282%2A3%29%2F5%2B1%2F5++
x=-6%2F5%2B1%2F5+
x=-5%2F5+
x=-1
solution:
(-1,3)
+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+-5x%2F2%2B1%2F2%2C+%284x%2B13%29%2F3%29+

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


If both linear equations are given in the form Ax+By=C, then solving the system by elimination is almost always easier than solving by substitution.

4x-3y+=+-13
5x%2B2y+=+1

Multiply the first equation by 2 and the second by 3 and add, eliminating y:

8x-6y+=+-26
15x%2B6y+=+3
23x+=+-23
x+=+-1

Substitute x = -1 in either original equation to solve for x:

4%28-1%29-3y+=+-13
-4-3y+=+-13
-3y+=+-9
y+=+3

ANSWER: (-1,3)