Solve 55-[11+[-15-(-8)]-21]-(7-(-11))

$$55 - [ 11 + [ - 15 - ( - 8 ) ] - 21 ] - ( 7 - ( - 11 ) )$$

Evaluate

$$54$$

Solution Steps

The opposite of -8 is 8.

$$55-\left(11-15+8-21\right)-\left(7-\left(-11\right)\right)$$

Add -15 and 8 to get -7.

$$55-\left(11-7-21\right)-\left(7-\left(-11\right)\right)$$

Subtract 7 from 11 to get 4.

$$55-\left(4-21\right)-\left(7-\left(-11\right)\right)$$

Subtract 21 from 4 to get -17.

$$55-\left(-17\right)-\left(7-\left(-11\right)\right)$$

The opposite of -17 is 17.

$$55+17-\left(7-\left(-11\right)\right)$$

Add 55 and 17 to get 72.

$$72-\left(7-\left(-11\right)\right)$$

The opposite of -11 is 11.

$$72-\left(7+11\right)$$

Add 7 and 11 to get 18.

$$72-18$$

Subtract 18 from 72 to get 54.

$$54$$

Factor

$$2\times 3^{3}$$