PLEASE HELP !! I HAVE TO DO IT FOR A WEEK BUT
I DON'T UNDERSTAND LOGARITHMS: '' ((

a). lg (x+1) +3 * lg (x+4)
b). log7 * 4-5x/7x+5
c). log x-4 (1-4x)
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(a) (8%) compute the probability of an even integer among the 100 integers 1! , 2! , 3! , until 100! (here n! is n factorial or n*(n-1)*(n-2) *… 1) (b) (16%) compute the probability of an even integer among the 100 integers: 1, 1+2, 1+2+3, 1+2+3+4, …., 1+2+3+… + 99, and 1+2+3+… + 100

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

20 solve 2(4 x + 3) < 5 x + 21. a) { x | x < 9} b) { x | x > -5} c) { x | x > -9} d) { x | x < 5}