Explanation

Explanation

Explanation

Explanation

Explanation

Explanation

Explanation

To find the inverse of 3 in modulo 7, we need to find a number x such that:

3x ≡ 1 (mod 7)

We can try multiplying 3 by each number from 1 to 6:

3 × 1 = 3

3 × 2 = 6

3 × 3 = 9 ≡ 2 (mod 7)

3 × 4 = 12 ≡ 5 (mod 7)

3 × 5 = 15 ≡ 1 (mod 7)

So, the inverse of 3 in modulo 7 is 5.

Explanation

Since f(x) = x^2 is always non-negative, there is no real x such that f(x) = -9.

So, the inverse image of -9 is the empty set:

f^(-1)(-9) = Ø

Explanation

"Called off" means to cancel or stop something, which fits the context of a strike being canceled.

Example: "The strike was called off after negotiations."

مذاکرات کے بعد ہڑتال کو بلایا گیا۔

Explanation

For matrices A × B ≠ B × A in general, so matrix multiplication is not commutative.

However, matrix addition is commutative and associative, and matrix multiplication is associative, but not commutative.