What is the number
A number is tripled, then 7 is subtracted from the result. The final answer is double the original number plus 5. What is the number?
Word Problem
A bridge is built across a river. One quarter of the bridge is over the left bank of the river and one third of the bridge is over the right bank. The river is 120 m wide. How long is the bridge?
Let the number be:
ReplyDeletex
Step 1: Tripled, then subtract 7
3x − 7
Step 2: This is equal to double the number plus 5
So,
3x − 7 = 2x + 5
Step 3: Solve the equation
3x − 7 = 2x + 5
Subtract 2x from both sides:
x − 7 = 5
Add 7 to both sides:
x = 12