Question

Answer 1

a: \(x\cdot2-35=-40\)

=>\(x\cdot2=-40+35=-5\)

=>\(x=-\dfrac{5}{2}\)

b: \(35-3x=-4\cdot5\)

=>\(35-3x=-20\)

=>\(3x=35-\left(-20\right)=35+20=55\)

=>3x=55

=>\(x=\dfrac{55}{3}\)

c: \(72+\left(x-3\right)\cdot5=-3\)

=>\(\left(x-3\right)\cdot5=-3-72=-75\)

=>\(x-3=-\dfrac{75}{5}=-15\)

=>x=-15+3=-12

d: \(-4x+32=16\)

=>\(-4x=16-32\)

=>\(-4x=-16\)

=>\(4x=16\)

=>\(x=\dfrac{16}{4}=4\)

e: \(-x^2+15=-1\)

=>\(-x^2=-1-15=-16\)

=>\(x^2=16\)

=>\(\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)

Answer 2

a) x.2 - 35 = -40

x.2 = -40 + 35

x.2 = -15

x = -15/ 2

b) 35 - 3.x = -4.5

35 - 3x = -20

3x = 35 - (-20)

3x = 55

x = 55/3

c) 72 + (x - 3).5 = -3

(x - 3).5 = -3 - 72

(x - 3).5 = -75

x - 3 = -75 : 5

x = -15 + 3

x = -12

d) -4x + 32 = 16

-4x = 16 - 32

-4x = -16

x = -16 : (-4)

x = 4

e) -x² + 15 = -1

-x² = -1 - 15

-x² = -16

x² = 16

x = 4 hoặc x = -4