GED Math Test #7 3 Flashcards

Solve the system: x + y = 10 and x − y = 4

Answer: x = 7, y = 3

Add the equations: 2x = 14, so x = 7. Substitute: 7 + y = 10, so y = 3. Check: 7 − 3 = 4 ✓.

A circle has a diameter of 10 cm. What is its circumference? (Use π ≈ 3.14)

Answer: 31.4 cm

Circumference = πd = 3.14 × 10 = 31.4 cm. The radius would be 5 cm, and area = πr² = 3.14 × 25 = 78.5 cm².

Which number is irrational?

Answer: √7

√7 ≈ 2.6457... is a non-repeating, non-terminating decimal, making it irrational. √9 = 3, 0.75, and 4/3 can all be expressed as fractions.

A worker earns $960 and saves 30% of it. How much does she save?

Answer: $288

Savings = 30% × $960 = 0.30 × 960 = $288. The remaining 70% = $672 is spent.

The angles of a quadrilateral measure 90°, 85°, 110°, and x°. What is x?

Answer: 75°

The sum of interior angles of a quadrilateral = 360°. x = 360° − 90° − 85° − 110° = 75°.

Convert 0.045 to a fraction in simplest form.

Answer: 9/200

0.045 = 45/1000. Simplify by dividing by GCF of 5: = 9/200. This fraction cannot be reduced further since 9 and 200 share no common factors.