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4x - 7y=105y = -3x + 10X=?

User Sash
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1 Answer

2 votes

Given:

4x - 7y = 105

y = -3x + 10

Let's find the solution for the system.

Since we have y = -3x + 10. Substitute (-3x + 10) for y in equation 1:

4x - 7(-3x + 10) = 105

• Apply distributive property:

4x - 7(-3x) -7(10) = 105

4x + 21x - 70 = 105

25x - 70 = 105

• Add 70 to both sides of the equation:

25x - 70 + 70 = 105 + 70

25x = 175

• Divide both sides by 25:


\begin{gathered} (25x)/(25)=(175)/(25) \\ \\ x=7 \end{gathered}

Substitute 7 for x in either equation.

Take the second equation:

y = -3x + 10

y = -3(7) + 10

y = -21 + 10

y = -11

Therefore, we have the solution:

x = 7, y = -11

ANSWER:

x = 7

User Ian Wood
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