-1 -4+3[-2+4(2times 5)-20]+(5times 4)

To solve the expression \(-1\{ -4+3[-2+4(2\times 5)-20]+(5\times 4)\} \), follow these steps:<br /><br />1. Calculate inside the innermost parentheses: \(2 \times 5 = 10\).<br /><br />2. Substitute back into the expression: <br /> \[<br /> -1\{ -4+3[-2+4(10)-20]+(5\times 4)\}<br /> \]<br /><br />3. Simplify inside the brackets:<br /> \[<br /> 4(10) = 40<br /> \]<br /> \[<br /> -2 + 40 - 20 = 18<br /> \]<br /><br />4. Substitute back into the expression:<br /> \[<br /> -1\{ -4+3[18]+(5\times 4)\}<br /> \]<br /><br />5. Calculate the multiplication and addition:<br /> \[<br /> 3[18] = 54<br /> \]<br /> \[<br /> 5 \times 4 = 20<br /> \]<br /><br />6. Substitute back into the expression:<br /> \[<br /> -1\{ -4 + 54 + 20 \}<br /> \]<br /><br />7. Simplify inside the braces:<br /> \[<br /> -4 + 54 + 20 = 70<br /> \]<br /><br />8. Apply the outer multiplication by \(-1\):<br /> \[<br /> -1 \times 70 = -70<br /> \]<br /><br />The final result is \(-70\).