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P-4x - 3y= -26-5x+2y= -21Find the solution to the system of equations shown above by graphing.A. X= 5, y= 2B. X= 5, y=3C. X= 2, y = 5D. x= 6, y= 2PLEASE EXPLAIN!!!how you do it

User Ervine
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1 Answer

4 votes

we will use the delete method

fist, We need an equation to have the variable with the same number but with the opposite sign, for this we can multiply the entire equation by a constant

will use the first equation


-4x-3y=-26

we can multiply with -5/4 to turn the -4 into 5


\begin{gathered} -4x((-5)/(4))-3y((-5)/(4))=-26((-5)/(4)) \\ \\ 5x+(15)/(4)y=(65)/(2) \end{gathered}

then, we will add the two equations


\begin{gathered} 5x+(15)/(4)y=(65)/(2)\text{ +} \\ \\ -5x+2y=-21 \\ ----------------- \\ (5-5)x((15)/(4)+2)y=((65)/(2)-21) \end{gathered}

we can simplify the equation


0x+(23)/(4)y=(23)/(2)

and solve Y


\begin{gathered} y=(23*4)/(23*2) \\ y=(4)/(2) \\ y=2 \end{gathered}

having Y we can replace in any initial equation and solve for X

I will use the second equation


\begin{gathered} -5x+2y=-21 \\ -5x+2(2)=-21 \\ -5x+4=-21 \\ -5x=-21-4 \\ -5x=-25 \\ x=(-25)/(-5) \\ x=5 \end{gathered}

and the solution is (5,2) or x=5 and y=2

User Leba
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