Explanation

"Sum of six and z" means 6 + z.

"Less than four" means the expression is less than 4 → 6 + z < 4.

Explanation

The square of 31 is:

31 × 31 = 961.

Explanation

The perfect square among these is 81 (since 9 × 9 = 81).

Explanation

The set {0, ±1, ±2, ±3, ±4, ...} includes all positive, negative integers, and zero.

This set is called the set of integers.

Explanation

30% = 30/100 = 0.3

Explanation

Explanation

Explanation

Collinear points are points that lie on the same straight line.

Example: Points A, B, and C on a ruler are collinear if they form a straight path.

Explanation

The multiplicative identity is the number which, when multiplied by any rational number, leaves it unchanged.

For rational numbers, that number is 1 because a × 1 = a.

Explanation

3/8 of 40 = (3/8) × 40 = 120/8 = 15