Question

alguém me ajuda

a)
$\sqrt{90} + 4$
b)
$2(3x + 4) = 7$
c)
$\frac{4}{5} + \sqrt{16}$
d)
$3x + 4 = - 2x + 10$
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Answer 1

a)

$\sqrt{90}~+~4~=\\\\\\=~\sqrt{2~.~3~.~3~.~5}~+~4\\\\\\=~\sqrt{3^2~.~10}~+~10\\\\\\=~\boxed{3\sqrt{10}~+~4}$

b)

$2.(3x+4)~=~7\\\\\\2\,.\,3x~+~2\,.\,4~=~7\\\\\\6x~+~8~=~7\\\\\\6x~=~-1\\\\\\\boxed{x~=~-\frac{1}{6}}$

c)

$\frac{4}{5}~+~\sqrt{16}~=\\\\\\=~\frac{4}{5}~+~4\\\\\\=~\frac{4\,.\,1~+~4\,.\,5}{5}\\\\\\=~\frac{4~+~20}{5}\\\\\\=~\boxed{\frac{24}{5}}$

d)

$3x~+~4~=~-2x~+~10\\\\\\3x~+~2x~=~10~-~4\\\\\\5x~=~6\\\\\\\boxed{x~=~\frac{6}{5}}$