Answer:
Step-by-step explanation:
<em>13).</em> ( x - 2 )( x + 6 ) = 9 × 20
x² + 4x - 12 = 180
x² + 4x - 192 = 0
( x - 12 )( x + 16 ) = 0
= <em>- 16</em>
= <em>12</em>
<em>14).</em> ( x + 4 )[( x + 4 ) + 3x ] = 8 × ( 8 + 19 )
( x + 4 )( 4x + 4 ) = 216
4( x + 4 )( x + 1 ) = 216
( x + 4 )( x + 1 ) = 54
x² + 5x + 4 - 54 = 0
x² + 5x - 50 = 0
( x - 5 )( x + 10 ) = 0
= <em>- 10</em>
= <em>5</em>
<em>15).</em> x( x + 16 ) = 15²
x² + 16x - 225 = 0
( x - 9 )( x + 25 ) = 0
= <em>- 25</em>
= <em>9</em>
<em>16).</em> Now is your turn. You can do it!