<s>[INST] How do I solve derivative of $(2x^2+x+3)(5x+7)$ using product rule. I've to find the derivative of
$$(2x^2+x+3)(5x+7)$$
Using product rule I get
$$(2x^2+x+3)×5+5×(2x^2+x+3)\\20x^2+10x+30$$
Which is wrong. Please help, where I went wrong.
 [/INST] $y=(2x^2+x+3)(5x+7) $ then
$$y'=(2x^2+x+3)'(5x+7)+(2x^2+x+3)(5x+7)'\\
=(4x+1)(5x+7)+5(2x^2+x+3) $$
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