For 5x + 20 and the multiplicative inverse of 5, write the product and then write the expression in standard form, if possible. Justify each step.

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

One number is 4 less than 3 times a second number. if 3 more than two times the first number is decreased by 2 times the second number, the result is 11. use the substitution method. what is the first number?

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.