180=3(1-$2^{n}$)/1-2
x^2-30=13x
33+2+3+4+6=
5d = 15
$\frac{1}{6x}$ +3=5
1*1 + x + 4 (-2) = -2
lcm of 70 and 273
C= $\frac{88}{ b+1}$
2×10^2-10^2
2*1 + x + (-2) = 0
