Question

(3б+2)+(7+3б)(7-3б)-12

Answer 1

(3b+2)+(7+3b)(7-3b)=3b+2+(7+3b)/2-12=3b+2+49+42b+9b-12=45b+2+49+9b/2-12=45b+39+9b/2=9b/2+45b+39
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/2 это во 2ой степени