Question

(5-2z) ao quadrado - (25+10z) ?
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Answer 1

$(5 - 2z) {}^{2} - (25 + 10z) \\ 5 {}^{2} - 2 \times 5 \times 2z + (2z) {}^{2} - 25 - 10z$

$25 - 20z + 4z {}^{2} - 25 - 10z \\ 25 - 25 - 20z - 10z + 4z {}^{2} \\ 0 -30z + 4z {}^{2} \\ 4z {}^{2} - 30z$