7²-0,4×5³

To solve this equation, we can follow the order of operations, which is commonly referred to as BEDMAS (Brackets, Exponents, Division and Multiplication, and Addition and Subtraction).

First, we calculate the exponent, as it comes before multiplication: 7² - 0,4 × 5³

7² equals 49, and 5³ equals 125: 49 - 0,4 × 125

Next, we perform the multiplication: 49 - (0,4 × 125)

0.4 × 125 equals 50: 49 - 50

Finally, we subtract 50 from 49: -1

Therefore, 7² - 0,4 × 5³ equals -1.