Answer:

Step-by-step explanation:
Multiply both sides by 7 to get rid of the denominator on the Right Side (RS). Do the same for the left side (LS) by multiplying both sides by 5 to get:

Simplify: 
Divide both sides of the equation by 7 to get: 
The answer is x=4 hope it helps
Answer:
20
Step-by-step explanation:
The whole straight line is 180 degrees. Add 3x, 2x, and 4x all together to get 9x. Then do 180/9x. This will give you 20. x=20.
Answer:
2 hours
Step-by-step explanation:
given that the calorie burn rates are:
swimming: 400 cal / hour
rollerblading: 600 cal / hour
If he swims for 3 hours, he will burn:
400 cal / hour x 3 hours
= 1200 cal
Since his goal is 2400 calories, the number of calories that he has left to burn after swimming is:
2400 - 1200
= 1200 calories.
Number of hours of rollerblading to burn 1200 calories
= 1200 calories ÷ 600 calories per hour
= 2 hours