3. Express each of the following lines in the form \( y=m x+c \) and hence write down the slope of the line: \( \begin{array}{lll}\text { (i) } x+y-4=0 & \text { (ii) } 3 x+y-5=0 & \text { (iii) } 2 x+3 y-7=0 \\ \text { (iv) } 5 x-2 y+3=0 & \text { (v) } 3 x+4 y-2=0 & \text { (vi) } 3 x-4 y+6=0\end{array} \)

To express each line in the form \( y = mx + c \), we rearrange each equation. The slope \( m \) can be directly obtained from the rearranged equations. (i) From \( x + y - 4 = 0 \): Rearranging gives \( y = -1x + 4 \). The slope is \( m = -1 \). (ii) From \( 3x + y - 5 = 0 \): Rearranging gives \( y = -3x + 5 \). The slope is \( m = -3 \). (iii) From \( 2x + 3y - 7 = 0 \): Rearranging gives \( 3y = -2x + 7 \) or \( y = -\frac{2}{3}x + \frac{7}{3} \). The slope is \( m = -\frac{2}{3} \). (iv) From \( 5x - 2y + 3 = 0 \): Rearranging gives \( -2y = -5x - 3 \) or \( y = \frac{5}{2}x + \frac{3}{2} \). The slope is \( m = \frac{5}{2} \). (v) From \( 3x + 4y - 2 = 0 \): Rearranging gives \( 4y = -3x + 2 \) or \( y = -\frac{3}{4}x + \frac{1}{2} \). The slope is \( m = -\frac{3}{4} \). (vi) From \( 3x - 4y + 6 = 0 \): Rearranging gives \( -4y = -3x - 6 \) or \( y = \frac{3}{4}x + \frac{3}{2} \). The slope is \( m = \frac{3}{4} \).