a. 5x – 16 = 40 + x
\(\Leftrightarrow 5x - x = 40 + 16\)
\(\Leftrightarrow 4x = 56\)
\(\Leftrightarrow x = 14\)
b. 4x – 10 = 15 – x
\(\Leftrightarrow 4x + x = 15 + 10\)
\(\Leftrightarrow 5x = 25\)
\(\Leftrightarrow x = 5\)
c. -12 + x = 5x – 20
\(\Leftrightarrow x - 5x = -20+12\)
\(\Leftrightarrow -4x=-8\)
\(\Leftrightarrow x=2\)
d. 7x – 4 = 20 + 3x
\(\Leftrightarrow 7x - 3x = 20 + 4\)
\(\Leftrightarrow 4x = 24\)
\(\Leftrightarrow x = 6\)
e. 5x – 7 = – 21 – 2x
\(\Leftrightarrow 5x + 2x = -21 + 7\)
\(\Leftrightarrow 7x = -14\)
\(\Leftrightarrow x=-2\)
f. x + 15 = 7 – 6x
\(\Leftrightarrow x + 6x = 7 - 15\)
\(\Leftrightarrow 7x = -8\)
\(\Leftrightarrow x = -\dfrac{8}{7}\)
g. 17 – x = 7 – 6x
\(\Leftrightarrow -x + 6x = 7 - 17\)
\(\Leftrightarrow 5x = -10\)
\(\Leftrightarrow x = -2\)
