The simplest form of the sum of the expression is 6x³√7
Surds are the square root of non perfect squares. Examples of perfect squares are 9, 16, 4, 25 e.t.c
Examples of surds are ; √50, √28 e.t.c
Solving the expression
√28x⁶ + 4√7x⁶
= √ 4 × √ 7x⁶ + 4√7x⁶
= 2√7x⁶ + 4√7x⁶
Represent √7x⁶ by y
= 2y + 4y
= 6y
2√7x⁶ + 4√7x⁶ = 6√7x⁶
= 6x³√7
Therefore, the simplest form of the sum of the expression is 6x³√7