5 - 4 + 7x + 1 = 7x + (5 - 4 + 1) = 7x + 2
NO SOLUTIONS:
<em>5 - 4 + 7x + 1 = 7x + a </em><em>(a - any real number, except 2)</em>
ONE SOLUTION:
<em>5 - 4 + 7x + 1 = bx + c </em><em>(b - any real number, except 7, c - any real number)</em>
INFINITELY MANY SOLUTIONS:
<em>5 - 4 + 7x + 1 = 7x + 2</em>
Examples:
2x + 3 = 2x + 5 <em>subtract 2x from both sides</em>
3 = 5 FALSE <em>(NO SOLUTIONS)</em>
2x + 3 = x - 4 <em>subtract x from both sides</em>
x + 3 = -4 <em>subtract 3 from both sides</em>
x = -7 (<em>ONE SOLUTION)</em>
2x + 3 = 2x + 3 <em>subtract 2x from both sides</em>
3 = 3 TRUE <em>(INFINITELY MANY SOLUTIONS)</em>