Question

Y = 2x - 3 Y = 4x + 1 ..... 2x - 3 = 4x + 1 what do i do next to get -2x = 4?

Answer 1

y = 2x - 3 --------- (1)
y = 4x + 1--------- (2)

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Equation (2) - (1) :
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(y - y) = (4x + 1) - (2x - 3)
0 = 4x + 1 - 2x + 3 // remove brackets
0 = 2x + 4 // combine like terms
2x + 4 = 0 // switch sides
2x = -4 // take away 4 from both sides
x = -2 ------ sub into (1) // Divide by 2 on both sides

y = 2(-2) - 3 // Sub x = -2 into equation (1)
y = -4 - 3 // Remove bracket
y = -7 // Combine like terms

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Answer: x = -2, y = -7
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