7-4+3x0+1=4
Because of PEMDAS: (P)arentheses (E)xponents (M)ultiplication (D)ivision A(ddition) S(ubtraction). Multiplication is basically equal to division, so you answer the equation in the way you read (left to right), if the problem presents multiplication first, you solve it however if the problem has division first, you solve it for division and the same rule applies for addition and subtraction.
So 7-4+3x0+1 will equal 4 because
3x0=0 (Multiplication, no division exists in this problem)
7-4=3 (Subtraction is first because you are doing it from the way you read left to right and subtraction comes before addition in this problem)
3+0+1=4 (Addition came after subtraction, so it is the last to be solved in this problem. And 3+0=3, 3+1=4.)
This is proof that 7-4+3x0+1=4, not any higher or lower than 4.