Solving Proportions
Grade 7 · Math · Proportional Relationships · Georgia, USA
Lesson Summary
Use cross-multiplication and other strategies to find the unknown value in a proportion.
Explanation
To solve a proportion like a/b = c/d, cross-multiply to get a × d = b × c, then solve for the unknown. You can also use equivalent fractions or unit rates to reach the same answer. Always double-check by plugging the answer back into the original proportion. This skill is essential for solving real-world problems involving scale, speed, and pricing.
Practice Questions
Q1: Solve for x: 3/7 = x/21.
Answer: Cross-multiply: 3 × 21 = 7x, so 63 = 7x and x = 9.
Q2: Solve for n: 8/n = 12/15.
Answer: Cross-multiply: 8 × 15 = 12n, so 120 = 12n and n = 10.
Q3: If 6 tickets cost $45, how much do 10 tickets cost?
Answer: Set up 6/45 = 10/x. Cross-multiply: 6x = 450, so x = 75. Ten tickets cost $75.
People Also Ask
What is Solving Proportions in Grade 7 Math?+
Solving Proportions is a lesson in the Proportional Relationships chapter of Grade 7 Math. It is part of the Georgia, USA school curriculum and covers key concepts that students need to understand at this level.
What grade level covers Solving Proportions?+
Solving Proportions is taught in Grade 7 as part of the Math curriculum in Georgia, USA.
How can I help my child with Proportional Relationships in Math?+
Start with the lesson summary and explanation on this page. Practice the questions provided, then use TutorTom for personalized, step-by-step help with Proportional Relationships topics.