\(a.10^2-x^2.10=10\)

\(100-10x^2=10\)

\(10x^2=90\)

\(x^2=9\)

\(x=\pm3\)

\(b.3^4-3x^2=2.3^3\)

\(81-3x^2=18\)

\(3x^2=63\)

\(x^2=21\)

\(x=\pm\sqrt{21}\)

\(d.2^8-x^3-32=156\)

\(256-x^3-32=156\)

\(224-x^3=156\)

\(x^3=68\)

\(x=\sqrt[3]{68}\)

a/ \(7^n-3^5=10^2\)

\(7^n-243=100\)

\(7^n=343\)

\(n=3\)

b/ 125 - 25n=100

25n=125-100

25n=25

n=1