The perimeter of the equilateral triangle represented the expression 21x + 15. The perimeter is 78 units. Find the value of x and the length of each side.

The two-way table shows the number of people whose hobbies are reading or solving puzzles and who either ride a motorcycle or don’t ride a motorcycle. among people whose hobby is reading, what is the relative frequency of not riding a motorcycle? express your answer as a decimal, and round it to the nearest hundredth if necessary. enter your answer in the box. reading solving puzzles ride a motorcycle 7 3 don't ride a motorcycle 5 9

Each month, a shopkeeper spends 5x + 14 dollars on rent and electricity. if he spends 3x−5 dollars on rent, how much does he spend on electricity? for which value(s) of x is the amount the shopkeeper spends on electricity less than $100? explain how you found the value(s).

Mrs. gehrke said cheddar weighs 16.8 pounds. he actually weighs 15.2 pounds. what is the percent error?