Find A and B
Two numbers, A and B, satisfy the following conditions:
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The sum of A and B is 30.
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If you double A and subtract B, you get 10.
What are the values of A and B?
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?
We are given two equations:
ReplyDeleteA + B = 30
2A - B = 10
Let’s solve this step-by-step:
Step 1: From equation 1, express B in terms of A:
A + B = 30
→ B = 30 - A
Step 2: Substitute into equation 2:
2A - B = 10
→ 2A - (30 - A) = 10
→ 2A - 30 + A = 10
→ 3A - 30 = 10
→ 3A = 40
→ A = 40 ÷ 3
→ A = 13⅓
Step 3: Find B:
B = 30 - A
→ B = 30 - 13⅓
→ B = 16⅔
Final Answer:
A = 13⅓
B = 16⅔