有冇人可以教下我解方程~q

a.(5^x)^2+5^x+1 -6=0 呢題有個5^x+1 之後跟住係-6唔
連埋5既次方
b. 1/x-3 -x/x+2=1 呢條都唔識
唔知係唔係感計1(x+2)-x(X-3)/(x-3)(x+2)=1
1(x+2)-x(x-3)=(x-3)(x+2)應該係感但係之後又唔識


c.x^8-7x^4-144=0 之後我諗應該係感做
(x^4+9)(x^4-16)跟住都唔識


唔該曬你地既請教