Answer: 6(7+x) is an equivalent expression of the given expression.
Explanation: Since, given expression is 42 + 6 x -----(1)
And, In distributive property, we distribute a number (with its operation) to the numbers enclosed by a bracket.
For example if there is an expression 2(3+5) then by distribution property under multiplication we can write 2(3+5)=2×3+2×5
And reverse of this property also exists which change the the expression 2×3+2×5 to 2(3+5).
From equation (1) we can write, 42+6x= 6×7+6×x
Thus, by reverse of distributive property we can write 42+6x= 6(7+x).