First decompose the factor, and then evaluate: 4a**2(x+7)-3(x+7), where a=-5, x=3.
先分解因式，再求值：4a**2(x+7)-3(x+7)，其中a=-5，x=3．
<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<gadget id="calculator">(-5) ** 2</gadget>
<output>25</output>

<gadget id="calculator">4 * 25</gadget>
<output>100</output>

<gadget id="calculator">100 - 3</gadget>
<output>97</output>

<gadget id="calculator">10 * 97</gadget>
<output>970</output>

<result>970</result>