800-(90×x+17)=423

Let's solve the equation for x step by step:

800 - (90×x + 17) = 423

First, distribute the negative sign inside the parentheses (this is the same as distributing -1):

800 - 90×x - 17 = 423

Combine the constant terms on the left side:

783 - 90×x = 423

Next, isolate the term with x on one side by subtracting 783 from both sides:

783 - 90×x - 783 = 423 - 783

This simplifies to:

-90×x = -360

Now, to solve for x, divide both sides by -90:

-90×x / -90 = -360 / -90

This gives us:

x = 4

So, the solution to the equation is x = 4.