Bài $1$.
$A= -1500 - {5^3 .2^3 -11[7^2-5.2^3(11^2-121)]}$
$A = -1500 - {125.8 - 11.[49 - 5.2^3.(121-121)]}$
$A = -1500 - [1000 - 11.(49-0)]$
$A = -1500 - (1000 - 539)$
$A = -2500 + 539$
$A = -1961$.
Bài $2$.
$a$) $15-x = 4x-59$
$⇔ 4x+x = 15 + 59$
$⇔ 5x = 74$
$⇔ x = \dfrac{74}{5}$.
$b$) $7x-4 = 20+3x$
$⇔ 7x-3x = 20+4$
$⇔ 4x = 24$
$⇔ x = 6$.
$c$) $x+15 = 20-4x$
$⇔ x+4x = 20-15$
$⇔ 5x=5$
$⇔ x=1$.
$d$) $5(x-6) - 2(x+3) = 12$
$⇔ 5x - 30 - 2x - 6 = 12$
$⇔ 3x - 36 = 12$
$⇔ 3x = 48$
$⇔ x = 16$.