Question

calcule o valor númerico das expressões:..​

Answer 1

Resposta e explicação passo a passo:

$a)\\\\3x+5--->x=-6\\\\3(-6)+5\\\\-18+5\\\\-13$

$b)\\\\2a+7b--->a=-3\ e\ b=\frac{1}{7}\\\\2(-3)+7(\frac{1}{7})\\-6+\frac{7}{7}\\\\-6+1\\\\-5$

$c)\\\\a^2+3a--->a=\frac{1}{2}\\\\(\frac{1}{2})^2+3(\frac{1}{2})\\\\\frac{1}{4}+\frac{3}{2}--->MMC=4\\\\\frac{1+2(3)}{4}\\\\\frac{1+6}{4}\\\\\frac{7}{4}$

$d)\\\\a^2-2ab+b^2--->a=-5\ e\ b=2\\\\(-5)^2-2\times-5\times2+2^2\\\\25+20+4\\\\49$