15•10+30-20 •5=

To solve the expression \(15 \cdot 10 + 30 - 20 \cdot 5\), follow the order of operations (multiplication and division before addition and subtraction):

1. Calculate the multiplications:

   • \(15 \cdot 10 = 150\)
   • \(20 \cdot 5 = 100\)

2. Substitute these values back into the expression: \[ 150 + 30 - 100 \]

3. Now perform the addition and subtraction:

   • First add \(150 + 30 = 180\)
   • Then subtract \(180 - 100 = 80\)

So, the result of the expression is \(80\).