Mathematics Flashcards

Which expression represents the area of a circle with diameter d?

Answer: πd²/4

Radius = d/2, so Area = π(d/2)² = πd²/4.

What is the value of x if 5(x − 2) = 3(x + 4)?

Answer: x = 11

5x − 10 = 3x + 12 → 2x = 22 → x = 11.

A cylinder has a radius of 5 cm and a height of 10 cm. What is its volume? (Use π ≈ 3.14)

Answer: 785 cm³

V = πr²h = 3.14 × 25 × 10 = 785 cm³.

On a number line, which value is closest to √50?

Answer: 7

√49 = 7 and √64 = 8, so √50 is just slightly above 7.

A recipe calls for 2½ cups of flour to make 24 cookies. How many cups are needed for 60 cookies?

Answer: 6¼ cups

60 ÷ 24 = 2.5, so 2.5 × 2.5 = 6.25 = 6¼ cups.

What is the value of −3² − (−4)²?

Answer: −25

−3² = −9 and −(−4)² = −16; −9 + (−16) = −25.

The equation y = −2x + 6 crosses the y-axis at which point?

Answer: (0, 6)

The y-intercept occurs at x = 0; y = −2(0) + 6 = 6, so the point is (0, 6).