Now we will multiply the two first matrices on LHS using the formula c_ij = a_i1b_1j + a_i2b_2j + … + a_inb_nj, we get

Again multiply these two LHS matrices, we get

⇒ x² – 2x – 40 + 2x – 8 = 0

⇒ x² – 48 = 0. This is form of quadratic equation, we will solve this, we get

⇒ x² = 48 ⇒ x² = 16×3

This gives, x = ±4√3 is the required solution of the matrices.