Posted by gary on Monday, July 8, 2013 at 11:15pm.
#1.
First, we represent the unknown using variables.
Let x = Ed's age
Let 59 - x = father's age (since according to the first statement, the sum of their ages is 59)
Then we setup the equation. According to the second statement,
Father's age = 4*(Ed's age) - 11
In variables,
59 - x = 4x - 11
59 + 11 = 4x + x
70 = 5x
(5x)/5 = (70)/5
x = 14 years old [Ed's age]
#2.
Represent the unknown with a variable.
Let x = number
Then setup the equation using the given conditions.
7x - 5 = 58
Solving for x,
7x = 58 + 5
7x = 63
x = 9
#3.
Represent the unknown with a variable.
Let x = number
Setup the equation:
(1/2)x + (1/3)x = 30
Solve for x. (Recall how to add fractions too)
(3/6)x + (2/6)x = 30
[(5/6)x]*(6/5) = 30*6/5
x = 36
Hope this helps~ :)
4. The perimeter of a tgriangle is 44 inches. If one side is 5 inches longer than the smallest side and the largest side is 1 inch less than twice the smallest side, how many inches are there in the smallest side?
#4.
Represent the unknowns with a variable.
Let x = smallest side
Let x + 5 = larger side (according to the 2nd statement)
Let 2x - 1 = largest side (according to the 2nd statement)
Then setup the equation. Recall that the perimeter of a triangle is just the sum of the lengths of its sides:
x + x + 5 + 2x - 1 = 44
Now solve for x. Units in inches.
Hope this helps~ :)
thank you for help
I have two more question, I hope you can help me.
1. A hotel has 120 rooms. If the number of double room is 8 more than three times the number of single rooms, how many single rooms does the hotel have?
2. A mechanic earns $5 more per hour than his helper. On a six-hour job the two men earn a total of $114. how much does each earn per hour?