Examples on these questions?

Question

1)x/x+3 = 5/x+7
2)Stan was trying to guess Melanies age. She told him her age was an even number and a multiple of three. What could be melanies age?
3)What is the solution set of the equation x/5 +x/2 =14
4)Walter is a waiter at the Towne Diner. He earns a daily wage of $50, plus tips that are equal to 15% of the total cost of the dinners serves. What was the total cost of the dinners he served if he earned $170 on Tuesday?
5)Sean knows the length of the base, b, and the area, A, of a triangular window in his bedroom. Which formula could he use to find the height,h, of this window?

Answer 1

Are you looking for the answers to these questions or examples like them?

Also please clarify is (1) is
(x/x) + 3 = (5/x) + 7

or

x/(x+3) = 5/(x+7)
In this latter case, multiply both sides by (x+3) then multiply both sides by (x+7) and solve for x

(2) Melanie could be 6x where x is a positive integer
ie, 6, 12, 18, 666yo etc.

(3) find the lowest common denominator
(2x + 5x)/10 = 14
then solve for x

(4) cost of dinners is x
tips = 15x/100
total = 50 + 15x/100 = 170
Solve for x

(5) Use the formula for area of a triangle (A = 1/2 x base x height)
Rearrange in terms of height to get a new formula
-multiply both sides by 2
-divide both sides by b

Answer 2

1) x/x+3=5/x+7
or,1+3=5/x+7
or,4=5/x+7
or,5/x=4-7
or,5/x=-3
or,-3x=5
or, x= -5/3

2) it can be any multiple of 3 which is also a multiple of 2. for example, 6,12,24,etc.

3) x/5+x/2=14
or, (2x+5x)/10=14
or, 7x/10=14
or, 7x=140
or, x=20

4)total earnings=50+15% of x=170
or, 0.15*x=170-50
or, 0.15x=120
or, x=800

5)area of a triangle= 1/2*base*height
or, 2*area of the triangle=base*height
or, base*height= 2*area of the traingle
or, height= (2*area of the triangle)/base